Azo compound and ink containing the compound

ABSTRACT

An object of the present invention is to provide an ink containing an azo compound which is excellent in solubility in a solvent and has a high extinction coefficient. The present invention relates to an ink comprising a solvent having a relative permittivity of 3 or less, as measured at a frequency of 1 kHz and at 22° C. and having a solubility in water of 20 mg/L or less at 25° C. and a specific azo compound.

TECHNICAL FIELD

The present invention relates to an azo compound and an ink containingthe compound. More particularly, the invention relates to an azocompound having a specific chemical structure and an ink which containsthe compound and is useful as a display material or for an opticalshutter.

BACKGROUND ART

An electrowetting display is an image display system which includes asubstrate and, disposed thereon, a plurality of pixels filled with twophases of an aqueous medium and an oil-based coloring ink, and in whichthe affinity of the aqueous medium/substrate interface is controlled foreach pixel by means of a voltage application on-off operation tospread/gather the oil-based coloring ink on the substrate and thereby animage is displayed (Non-Patent Document 1). The colorants for use inelectrowetting displays are required to have high solubility inlow-polarity solvents and the other properties (Patent Document 1 andPatent Document 2).

Patent Documents 3 to 6 show polyester fiber dye colorants each using adisazo compound excellent in fastness. Moreover, Patent Document 7 showsa cyan colorant for use in thermal-transfer sheets, which easily atleast sublimes or thermally diffuses and an ink composition using thecolorant, and mentions media for ink preparation.

PRIOR ART LITERATURE Patent Documents

-   Patent Document 1: JP-T-2007-531917 (The term “JP-T” as used herein    means a published Japanese translation of a PCT patent application.)-   Patent Document 2: International Publication WO2010/031860-   Patent Document 3: JP-A-57-109860-   Patent Document 4: JP-A-57-111356-   Patent Document 5: JP-A-57-125262-   Patent Document 6: JP-A-57-125263-   Patent Document 7: JP-A-3-256793

Non-Patent Document

-   Non-Patent Document 1: “Nature”, (Great Britain), 2003, Vol. 425,    pp. 383-385

SUMMARY OF THE INVENTION Problems that the Invention is to Solve

However, the above Patent Document 2 does not specifically shows acolorant having a high solubility in low-polar solvents and a highextinction coefficient.

Moreover, there are descriptions on dye colorants in the above PatentDocuments 3 to 6 and there is a description of a colorant and media forink adjustment in the above Patent Document 7. However, these documentsneither describe nor suggest solubility of the colorants in solvents,particularly solubility in low-polar solvents.

An object of the invention is to provide an ink containing a compound,which is excellent in solubility in low-polarity solvents and has a highextinction coefficient, and an ink containing the compound.

Means for Solving the Problems

The present inventors diligently made investigations in order toovercome the problems described above. As a result, they have found thatan azo compound having a certain chemical structure is excellent insolubility in solvents and further has a high molar extinctioncoefficient. The invention has been accomplished on the basis of thesefindings.

Namely, essential points of the invention are described in the following(1) to (15).

(1) An ink comprising: a solvent having a relative permittivity of 3 orless, as measured at a frequency of 1 kHz and at 22° C., and having asolubility in water of 20 mg/L or less at 25° C.; and an azo compound,the azo compound being represented by the following general formula (I):

wherein

R¹, R², D¹, A¹, and A² each independently represent an arbitrarysubstituent,

m represents an integer of 1 to 4, and when m is 2 or larger, two ormore D¹ groups present in one molecule may be the same or different, and

X represents a nitrogen atom or an optionally substituted methine group.

(2) The ink according to the item (1) above, wherein the solventcontains at least one selected from the group consisting of hydrocarbonsolvents, silicone oils, and fluorocarbon solvents.

(3) The ink according to the item (1) or (2) above, wherein the productof a molar extinction coefficient ε (L·mol⁻¹·cm⁻¹) at theabsorption-maximum wavelength of an n-decane solution of the azocompound and a saturated concentration C (mol·L⁻¹) of the azo compoundin n-decane at 5° C., εC, is 1,000 cm⁻¹ or larger.

(4) The ink according to any one of the items (1) to (3) above, whichfurther comprises at least one selected from the group consisting ofheterocyclic compounds, cyanovinyl compounds, and anthraquinonecompounds.

(5) The ink according to the item (4) above, wherein the heterocycliccompound is at least one selected from the group consisting of thefollowing general formulae (III) to (V):

wherein

R¹⁰¹, R¹⁰², D³, and D⁴ each independently represent an arbitrarysubstituent,

e represents an integer of 1 to 5, and when e is 2 or larger, two ormore D³ groups present in one molecule may be the same or different, and

g represents an integer of 1 to 4, and when g is 2 or larger, two ormore D⁴ groups present in one molecule may be the same or different;

wherein

R²⁰¹, R²⁰², R²⁰³, R²⁰⁴, R²⁰⁵, R²⁰⁶, R²⁰⁷, and R²⁰⁸ each independentlyrepresent an arbitrary substituent and

Z represents a nitrogen atom or an optionally substituted methine group;

wherein

R³⁰¹, R³⁰², D⁵, and D⁶ each independently represent an arbitrarysubstituent,

l represents an integer of 1 to 4, and when 1 is 2 or larger, two ormore D⁵ groups present in one molecule may be the same or different, and

j represents an integer of 1 to 4, and when j is 2 or larger, two ormore D⁶ groups present in one molecule may be the same or different.

(6) The ink according to the item (4) or (5) above, wherein thecyanovinyl compound is represented by the following general formula(VI):

wherein

R⁴⁰¹, R⁴⁰², R⁴⁰³, R⁴⁰⁴, and D⁷ each independently represent an arbitrarysubstituent and

r represents an integer of 1 to 4, and when r is 2 or larger, two ormore D⁷ groups present in one molecule may be the same or different.

(7) The ink according to any one of the items (4) to (6) above, whereinthe anthraquinone compound is represented by the following generalformula (VII):

wherein

D⁸ represents an arbitrary substituent and t represents an integer of 1to 8, and when t is 2 or larger, two or more D⁸ groups present in onemolecule may be the same or different.

(8) The ink according to any one of the items (1) to (7) above, which isfor use in a display or optical shutter.

(9) A display comprising a display part containing the ink according toany one of the items (1) to (7) above, wherein an image is displayed bycontrolling voltage application to the display part.

(10) The display according to the item (9) above, wherein the displaypart further contains electrophoretic particles or an aqueous medium.

(11) The display according to the item (9) or (10) above, wherein animage is displayed by changing a colored state by means of voltageapplication.

(12) The display according to any one of the items (9) to (11) above,wherein an image is displayed by an electrowetting system or anelectrophoretic system.

(13) An electronic paper which comprises the display according to anyone of the items (9) to (12) above.

(14) An azo compound represented by the following general formula(VIII):

wherein

R⁶⁰¹ and R⁶⁰² each independently represent an optionally substitutedbranched alkyl group having 7 to 20 carbon atoms,

D⁹ represents a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, an —NHCOR⁶⁰³ group, or an—NHSO₂R⁶⁰⁸ group,

R⁶⁰³ and R⁶⁰⁸ each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms,

a represents an integer of 1 to 4, and when a is 2 or larger, two ormore D⁹ groups present in one molecule may be the same or different,

A³ represents a halogen atom, a cyano group, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, an optionally substituted heteroarylgroup having 2 to 20 carbon atoms, an optionally substituted alkoxygroup having 1 to 20 carbon atoms, or a —COOR⁶⁰⁴ group,

R⁶⁰⁴ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms,

A⁴ represents a halogen atom, an optionally substituted alkyl grouphaving 1 to 20 carbon atoms, an optionally substituted alkenyl grouphaving 2 to 20 carbon atoms, an optionally substituted alkylcarbonylgroup having 2 to 20 carbon atoms, an optionally substitutedalkoxycarbonyl group having 2 to 20 carbon atoms, a formyl group, anR⁶⁰⁵OOC(NC)C═CH— group, or an NC(NC)C═CH— group,

R⁶⁰⁵ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms,

X² represents a nitrogen atom, or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁶⁰⁷ group as a substituent, and

R⁶⁰⁷ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms.

(15) An azo compound represented by the following general formula (IX):

wherein

R⁷⁰¹ and R⁷⁰² each independently represent an optionally substitutedbranched alkyl group having 5 to 20 carbon atoms,

D¹¹ represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted alkoxy group having 1 to 20 carbon atoms, an —NHCOR⁷⁰³group, or an —NHSO₂R⁷⁰⁸ group,

R⁷⁰³ and R⁷⁰⁸ each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms,

d represents an integer of 1 to 4, and when d is 2 or larger, two ormore D¹¹ groups present in one molecule may be the same or different,

A⁵ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, anoptionally substituted heteroaryl group having 2 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 20 carbon atoms, or a—COOR⁷⁰⁴ group,

R⁷⁰⁴ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms,

D¹⁰ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 20 carbon atoms, a—COOR⁷⁰⁶ group, a —COR⁷⁰⁹ group, or an —OCOR⁷¹⁰ group,

b represents an integer of 1 to 5, and when b is 2 or larger, two ormore D¹⁰ groups present in one molecule may be the same or different,

R⁷⁰⁶, R⁷⁰⁹, and R⁷¹⁰ each independently represent an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, or an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms,

X³ represents a nitrogen atom, or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁷⁰⁷ group as a substituent, and

R⁷⁰⁷ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms.

Advantage of the Invention

The azo compound according to the invention has a high solubility inoil-soluble solvents and can hence be used widely as inks. Furthermore,since an ink containing the azo compound according to the invention hasa high solubility in low-polarity solvents and also a high molarextinction coefficient, the ink is useful as an ink for use in displaysand optical shutters.

Furthermore, as the displays, the ink is especially useful in a displaywhich has a display part containing an ink and in which an image isdisplayed by controlling voltage application to the display part, adisplay in which an image is displayed by changing a colored state bymeans of voltage application, and a display in which an image isdisplayed using electrophoretic particles or an aqueous medium in thedisplay part.

The electrophoretic particles herein are charged particles and may havecolor and contain plural kinds of electrophoretic particles at thedisplay part. Also, the aqueous medium is a fluid that may have colorand may have plural kinds of aqueous media at the display part.

Moreover, the azo compound and ink of the invention are particularlyuseful as an ink for use in a display of an electrowetting system or adisplay of an electrophoretic system.

Furthermore, the ink of the invention can provide satisfactory inks ofcolors such as black excellent in hue by using the azo compound of theinvention in combination with the other compound(s) and is also usefulas a member which functions as an optical shutter.

The ink according to the invention can be used in any devices so long asthey are display devices each having a display but is particularlyuseful for use in electronic papers.

MODES FOR CARRYING OUT THE INVENTION

Representative embodiments for carrying out the invention are explainedbelow in detail. However, the invention can be carried out with variousmodifications unless the modifications exceed the gist of the invention,and should not be construed as being limited to the followingembodiments.

Herein, “% by weight” and “% by mass” have the same meaning.

The ink according to the invention is an ink which includes a solventhaving a relative permittivity, as measured at 22° C. at a frequency of1 kHz, of 3 or less and having a solubility in water of 20 mg/L or lessat 25° C. and an azo compound, and is characterized in that the azocompound is represented by the following general formula (I):

wherein

R¹, R², D¹, A¹, and A² each independently represent an arbitrarysubstituent,

m represents an integer of 1 to 4, and when m is 2 or larger, two ormore D¹ groups present in one molecule may be the same or different, and

X represents a nitrogen atom or an optionally substituted methine group.

(Solvent)

In the display or optical shutter of the invention, a low-polaritysolvent is used as the solvent of the ink. The ink of the invention canbe used, for example, in a display device that has layers such as anaqueous layer and an oily layer and that is based on a phenomenon inwhich a layer breaks up or a layer moves aside. For clear displaying, itis necessary that the ink-containing layer should stably break up ormove aside without mingling with the aqueous layer and it is requiredthat the solvent should have low compatibility with water and have lowpolarity, etc. According to the invention, since the ink contains aspecific solvent and an azo compound, the oily layer can stably break upor move aside.

Meanwhile, in display devices utilizing electrophoresis, in whichcharged particles (electrophoretic particles) move in a solvent by theaction of an electric field, there are cases where a high permittivityof the solution is an obstacle to the operation of the display device.Use of the specific solvent and azo compound according to the inventionmakes it possible to color a solution without hindering the movement ofthe particles.

The solvent to be used in the invention has a relative permittivity of 3or less at 22° C., as measured at a frequency of 1 kHz. The relativepermittivity thereof is preferably 2.5 or less, more preferably 2.2 orless. There is no particular lower limit on the relative permittivitythereof. It is, however, preferable that the relative permittivity isgenerally 1.5 or higher, preferably 1.8 or higher.

A method for measuring the relative permittivity of a solvent will beshown in the Examples. Moreover, in the case where a plurality ofsolvents are mixed and used as a solvent for the ink, the relativepermittivity refers to relative permittivity of the mixed solvent.

When a layer in which the ink is contained has a relative permittivityfalling within an appropriate range, there are cases where the displaydevice can be operated without trouble. For example, in the case wherethe other layer, which contains no ink, is a liquid having electricalconductivity, polarity, or the like, such as water or a salt solution,when the relative permittivity of the solvent used in the ink-containinglayer falls within an appropriate range, there are cases where thelayers do not mingle with each other.

The solvent to be used in the invention has a solubility in water of 20mg/L or less at 25° C. The solubility is preferably 10 mg/L or less,more preferably 5 mg/L or less. There is no lower limit and lowersolubility is more preferable but the solubility is preferably 0.001mg/L or more. A method for measuring the solubility of a solvent inwater will be shown in Examples. Moreover, in the case where a pluralityof solvents are mixed and used as a solvent for the ink, the solubilityin water refers to solubility of the mixed solvent.

When the solubility in water is low, there are cases where the oil layerand the aqueous layer do not mingle with each other and the displaydevice can be operated without trouble.

The boiling point of the solvent of the invention is not particularlylimited. However, the boiling point thereof is preferably 120° C. orhigher, more preferably 150° C. or higher, and particularly preferably170° C. or lower. Moreover, it is preferably 300° C. or lower. When thesolvent has a boiling point which is not too high, this solvent hasneither too high a melting point nor too high a viscosity and there arecases where the display device can be operated without arousing atrouble therein. When the boiling point thereof is not too low, thesolvent has reduced volatility and there are cases where stability andsafety are obtained.

The viscosity of the solvent to be used in the invention is notparticularly limited. However, the viscosity at a solvent temperature of25° C. is preferably 0.1 mPa·s or more. Moreover, the viscosity ispreferably 10,000 mPa·s or less, more preferably 1,000 mPa·s or less,especially preferably 100 mPa·s or less. There are cases where when theviscosity of the solvent is not too large, the compound and the like areeasy to dissolve therein and the display device is satisfactorilyoperated.

The aforementioned solvents can be used alone or as a mixture thereof.

Specific examples thereof include hydrocarbon solvents, fluorocarbonsolvents, and silicone oils.

The hydrocarbon solvents include linear or branched aliphatichydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, andpetroleum naphtha.

Examples of the aliphatic hydrocarbon solvents and the alicyclichydrocarbon solvents include aliphatic hydrocarbon solvents such asn-decane, isodecane, decalin, nonane, dodecane, isododecane,tetradecane, hexadecane, and isoalkanes, and commercial products thereofinclude Isopar E, Isopar G, Isopar H, Isopar L, Isopar M (registeredtrademark, manufactured by Exxon Mobil Corporation), IP Solvent(registered trademark, manufactured by Idemitsu Petrochemical Co.,Ltd.), and Soltol (manufactured by Phillips Petroleum InternationalLtd.).

The aromatic hydrocarbon solvents include alkylnaphthalenes andtetraline.

The petroleum naphtha solvents include Shell S.B.R., Shellsol 70,Shellsol 71 (manufactured by Shell Sekiyu Kagaku K.K.), Pegasol(manufactured by Exxon Mobil Corporation), and Hisosol (manufactured byNippon Oil Corporation).

The fluorocarbon solvents are hydrocarbons mainly substituted withfluorine. Examples thereof include perfluoroalkanes represented byC_(n)F_(2n+2), such as C₇F₁₆ and C₈F₁₈, and commercial products thereofinclude Fluorinert PF5080 and Fluorinert PF5070 (manufactured bySumitomo 3M Ltd.).

Fluorochemical inert liquids include Fluorinert FC Series (manufacturedby Sumitomo 3M Ltd.), fluorocarbons include Krytox GPL Series(registered trademark, manufactured by DuPont Japan Ltd.),chlorofluorocarbons include HCFC-141b (manufactured by DaikinIndustries, Ltd.), and iodinated fluorocarbons, such as F(CF₂)₄CH₂CH₂Iand F(CF₂)₆I, include I-1420 and I-1600 (manufactured by Daikin FineChemical Laboratory Co., Ltd.) and the like.

Examples of the silicone oils include low-viscosity syntheticdimethylpolysiloxane, and commercial products thereof include KF96L(manufactured by Shin-Etsu Silicone) and SH200 (manufactured by DowCorning Toray Silicone Co., Ltd.).

Preferably, the solvent contains at least one selected from the groupconsisting of hydrocarbon solvents, fluorocarbon solvents, and siliconeoils. The content of these solvents is generally 50% by mass or more,preferably 70% by mass or more, more preferably 90% by mass or more.

In the case where the solvent is used as a mixture, when the interactionbetween the solvents is small as in the invention, the relativepermittivity of the mixed solvent can be approximated by multiplyingrelative permittivity of each solvent constituting the mixed solvent byeach volume fraction and summing respective products. Moreover, when theinteraction between the solvents is similarly small, solubility of themixed solvent in water can be approximated by a value obtained bymultiplying solubility of each solvent constituting the mixed solvent inwater by each molar fraction and summing respective products.

The ink of the invention contains a specific solvent and an azo compoundand is obtained by dissolving the azo compound and other compounds,additives, and the like to be used according to need, in the solvent.

In connection with the term “dissolving”, the azo compound need not havebeen completely dissolved in the solvent so long as the azo compoundpasses through a filter of about 0.1 μm and the solution is in such astate that the extinction coefficient thereof can be measured, or thesolution may be in such a state that fine particles of the compound aredispersed therein.

(Azo Compound)

The azo compound of the invention has a chemical structure representedby the aforementioned general formula (I).

Specific examples of R¹, R², D¹, A¹, A² D¹, m, and X to be used in theabove general formula (I) will be described in the following.

R¹ and R² each independently represent an arbitrary substituent. Thearbitrary substituent is not particularly limited but R¹ and R² eachindependently are preferably an optionally substituted alkyl grouphaving 1 to 20 carbon atoms from the viewpoint of solubility insolvents.

The alkyl groups represented by R¹ and R² which may possess asubstituent include linear alkyl groups such as methyl, ethyl, propyl,butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl groups;branched alkyl groups such as isopropyl, isobutyl, sec-butyl,tert-butyl, isooctyl, and isononyl groups; cyclic alkyl groups such ascyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl,cyclohexylmethyl, and 4-butylmethylcyclohexyl groups; and the like.

The number of carbon atoms of R¹ and R² is preferably 2 or more, morepreferably 5 or more, particularly preferably 7 or more. Moreover, thenumber of carbon atoms is preferably 16 or less, more preferably 12 orless. When the number of carbon atoms falls within an appropriate range,there are cases where the compound is excellent in solubility insolvents and can have a high gram extinction coefficient.

Furthermore, at least one of R¹ and R² is preferably a branched alkylgroup and further, at least one thereof is preferably a branched alkylgroup having 5 to 20 carbon atoms, still further preferably a branchedalkyl group having 7 to 20 carbon atoms. Moreover, it is more preferablethat R¹ and R² both are a branched alkyl group from the viewpoint ofsolubility.

The substituent which may be optionally possessed by the alkyl groups ofR¹ and R² is not particularly limited. However, specific examplesthereof are preferably low polar substituents from the standpoint ofsolubility in solvents and examples thereof include halogen atoms suchas fluorine, chlorine, bromine, and iodine atoms; alkoxy groups having 1to 20 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, isobutoxy,sec-butoxy, and tert-butoxy groups; alkoxycarbonyl groups having 2 to 20carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, andt-butoxycarbonyl groups; a cyano group; and the like.

D¹ represents an arbitrary substituent. The arbitrary substituent is notparticularly limited as far as it is a known substituent to be used at acoupler part of an azo compound without particular limitation.

It is particularly preferable that D¹ is a hydrogen atom, a halogenatom, an optionally substituted alkyl group having 1 to 20 carbon atoms,an optionally substituted alkoxy group having 1 to 20 carbon atoms, an—NHCOR³ group, or an —NHSO₂R⁸ group, since the azo compound hasexcellent solubility in solvents and further has a high molar extinctioncoefficient.

Moreover, m represents an integer of 1 to 4, and when m is 2 or larger,two or more D¹ groups present in one molecule may be the same ordifferent.

The alkyl group of D¹ which may possess a substituent has the samemeaning as the alkyl group exemplified in R¹ of the above generalformula (I) and the substituent which may be possessed also has the samemeaning.

As the alkyl group of D¹, the number of carbon atoms is preferably 16 orless, more preferably 10 or less, particularly preferably 6 or less.When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

The alkoxy group of D¹ which may possess a substituent specificallyincludes linear alkoxy groups such as methoxy, ethoxy, propoxy, butoxy,pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, phenoxy,naphthyloxy, dodecanoxy, thoxymethyl, methoxyethyl, methoxybutyl,ethoxymethyl, ethoxyethyl, ethoxybutyl, allyloxy,2,2,2-trifluoromethoxy, and trifluoroethoxy groups; branched alkoxygroups such as isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, andisooctyloxy groups; alkoxy groups having a cyclic structure, such ascyclopropoxy, cyclopentyloxy, cyclohexyloxy, cyclopropylmethyloxy,phenoxy, 4-butylphenoxy, 4-butylcyclohexyloxy,3-{2-(2-ethylhexyloxy)ethoxy}phenoxy, benzyloxy, and 1-naphthyloxygroups; and the like.

As the alkoxy group of D¹, the number of carbon atoms is preferably 16or less, more preferably 10 or less, particularly preferably 6 or less.When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

Moreover, the substituent which may be optionally possessed by thealkoxy group of D¹ is not particularly limited. However, specificexamples thereof include halogen atoms, alkoxy groups having 1 to 20carbon atoms, carbonyl groups having 1 to 20 carbon atoms, such asformyl, acetyl, benzoyl, carbazoyl, and phenylcarbonyl groups, and thelike.

R³ and R⁸ each independently represent an optionally substituted alkylgroup having 1 to 20 carbon atoms, an optionally substituted aryl grouphaving 6 to 20 carbon atoms, or an optionally substituted heteroarylgroup having 2 to 20 carbon atoms.

The alkyl group of each of R³ and R⁸ has the same meaning as the alkylgroup exemplified in R¹ of the above general formula (I) and eachsubstituent which may be possessed also has the same meaning. As thealkyl group of R³ and R⁸, the number of carbon atoms is preferably 16 orless, more preferably 10 or less, particularly preferably 6 or less.When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

The alkoxy group of each of R³ and R⁸ has the same meaning as the alkoxygroup exemplified in D¹ of the above general formula (I) and eachsubstituent which may be possessed also has the same meaning. As thealkoxy group of R³ and R⁸, the number of carbon atoms is preferably 16or less, more preferably 10 or less, particularly preferably 6 or less.When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

The aryl group of each of R³ and R⁸ is a group obtained by removing onehydrogen atom from a monocycle or a condensed ring obtained bycondensing 2 to 4 rings of the monocycles. Specific examples thereofinclude groups from a benzene ring, a naphthalene ring, an anthrathenering, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrenering, a benzpyrene ring, a chrysene ring, a triphenylene ring, anacenaphthene ring, a fluoranthene ring, a fluorene ring, and the like.

The heteroaryl group of each of R³ and R⁸ is a group obtained byremoving one hydrogen atom from a monocycle or a condensed ring obtainedby condensing 2 to 4 rings of the monocycles. Specific examples thereofinclude groups from a furan ring, a benzofuran ring, a thiophene ring, abenzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring,an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazolering, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrolering, a thienothiophene ring, a furopyrrole ring, a furofuran ring, athienofuran ring, a benzoisooxazole ring, a benzoisothiazole ring, abenzoimidazole ring, a pyridine ring, a pyradine ring, a pyridazinering, a pyrimidine ring, a triazine ring, a quinoline ring, anisoquinoline ring, a shinorine ring, a quinoxaline ring, aphenanthridine ring, a benzoimidazole ring, a pyrimidine ring, aquinazoline ring, a quinazolinone ring, an azulene ring, and the like.

The substituent which may be possessed by the aryl and heteroaryl groupsof R³ is not particularly limited. However, specific examples includehalogen atoms, alkyl groups having 1 to 20 carbon atoms, alkoxy groupshaving 1 to 20 carbon atoms, alkoxycarbonyl groups having 1 to 20 carbonatoms, and the like.

A¹ represents an arbitrary substituent. The arbitrary substituent is notparticularly limited but it is preferable that A¹ is a hydrogen atom, ahalogen atom, a cyano group, an optionally substituted alkyl grouphaving 1 to 20 carbon atoms, an optionally substituted aryl group having6 to 20 carbon atoms, an optionally substituted heteroaryl group having2 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to20 carbon atoms, or a —COOR⁴ group, since the azo compound has excellentsolubility in solvents and further has a high molar extinctioncoefficient.

The alkyl group of A¹ has the same meaning as the alkyl groupexemplified in R¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkyl group ofA¹, the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The alkoxy group of A¹ has the same meaning as the alkoxy groupexemplified in D¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkoxy group ofA¹, the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The aryl group of A¹ has the same meaning as the aryl group exemplifiedin R³ of the above general formula (I) and the substituent which may bepossessed also has the same meaning as the aryl group exemplified in R³of the above general formula (I). As the aryl group of A¹, for thereason of high solubility in solvents, an optionally substituted phenylgroup or naphthyl group is preferable. As the substituent which may bepossessed by the phenyl group or the naphthyl group, for the reason ofhigh solubility in solvents, a halogen atom, an optionally substitutedalkyl group having 1 to 10 carbon atoms, or an optionally substitutedalkoxy group having 1 to 10 carbon atoms is preferable.

The heteroaryl group of A¹ has the same meaning as the heteroaryl groupexemplified in R³ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning as the heteroaryl groupexemplified in R³ of the above general formula (I). As the heteroarylgroup of A¹, for the reason of high solubility in solvents, anoptionally substituted thienyl group is preferable. As the substituentwhich may be possessed by the thienyl group, for the reason of highsolubility in solvents, a halogen atom, an alkyl group having 1 to 10carbon atoms, or an alkoxy group having 1 to 10 carbon atoms ispreferable.

R⁴ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms.

The alkyl group of R⁴ specifically has the same meaning as the alkylgroup exemplified in R¹ of the above general formula (I) and thesubstituent which may be possessed also has the same meaning. As thealkyl group of R⁴, the number of carbon atoms is preferably 16 or less,more preferably 10 or less, particularly preferably 6 or less. When thenumber of carbon atoms falls within an appropriate range, there arecases where the compound is excellent in solubility in solvents and canhave a high gram extinction coefficient.

The aryl group of R⁴ specifically has the same meaning as the aryl groupexemplified in R³ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning as the aryl groupexemplified in R³ of the above general formula (I). The heteroaryl groupof R⁴ specifically has the same meaning as the heteroaryl groupexemplified in R³ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning as the heteroaryl groupexemplified in R³ of the above general formula (I).

A² represents an arbitrary substituent. The arbitrary substituent is notparticularly limited but includes an optionally substituted alkyl grouphaving 1 to 20 carbon atoms, a halogen atom, an optionally substitutedalkenyl group having 2 to 20 carbon atoms, an optionally substitutedalkylcarbonyl group having 2 to 20 carbon atoms, an optionallysubstituted alkoxycarbonyl group having 2 to 20 carbon atoms, a formylgroup, an R⁵OOC(NC)C═CH— group, an NC(NC)C═CH— group, or a substituentrepresented by the following general formula (II):

wherein

D² represents an arbitrary substituent, n represents an integer of 1 to5, and when n is 2 or larger, two or more D² groups present in onemolecule may be the same or different.

The alkyl group of A² has the same meaning as the alkyl groupexemplified in R¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkyl group ofA², the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

In the alkenyl group of A², the position of the carbon-carbonunsaturated bond is not particularly limited and the alkenyl group mayhave a plurality of unsaturated bonds. Also, the group may be linear orbranched and may have an arbitrary substituent. The alkenyl groupincludes a vinyl group, a propenyl group, a hexenyl group, and the like.Of these, the alkenyl group preferably has 3 or more carbon atoms.Moreover, the number of carbon atoms is preferably 16 or less, morepreferably 12 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The alkyl group contained in the alkylcarbonyl group of A² includesthose having the same meaning as the alkyl group exemplified in R¹ ofthe above general formula (I) and the number of carbon atoms of thealkyl group is preferably 18 or less, more preferably 16 or less.

The alkoxy group contained in the alkylcarbonyl group of A² includesthose having the same meaning as the alkoxy group exemplified in D¹ ofthe above general formula (I) and the number of carbon atoms of thealkoxy group is preferably 18 or less, more preferably 16 or less.

When the number of carbon atoms of A² falls within an appropriate range,there are cases where the compound is excellent in solubility insolvents and can have a high gram extinction coefficient.

The substituent which may be possessed by the alkylcarbonyl group of A²is not particularly limited but specific examples include alkoxy groupshaving 1 to 20 carbon atoms. The substituent which may be possessed bythe alkoxycarbonyl group of A² is not particularly limited but specificexamples include alkyl groups having 1 to 20 carbon atoms. Thesubstituent which may be possessed by the alkenyl group of A² is notparticularly limited but specific examples include alkyl groups having 1to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, andalkoxycarbonyl groups having 2 to 20 carbon atoms.

R⁵ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms.

The alkyl group of R⁵ specifically has the same meaning as the alkylgroup exemplified in R¹ of the above general formula (I) and thesubstituent which may be possessed also has the same meaning. As thealkyl group of R⁵, the number of carbon atoms is preferably 16 or less,more preferably 10 or less, particularly preferably 6 or less. When thenumber of carbon atoms falls within an appropriate range, there arecases where the compound is excellent in solubility in solvents and canhave a high gram extinction coefficient.

The aryl group of R⁵ specifically has the same meaning as the aryl groupexemplified in R³ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning as in the case of thearyl group exemplified in R³ of the above general formula (I).

The heteroaryl group of R⁵ specifically has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I) andthe substituent which may be possessed also has the same meaning as inthe case of the heteroaryl group exemplified in R³ of the above generalformula (I).

D² represents an arbitrary substituent and is not particularly limitedbut specifically, D² is preferably a hydrogen atom, a halogen atom, acyano group, an optionally substituted alkyl group having 1 to 20 carbonatoms, an optionally substituted alkoxy group having 1 to 20 carbonatoms, a —COOR⁶ group, a —COR⁹ group, or an —OCOR¹⁰ group, since the azocompound has excellent solubility in solvents and further has a highmolar extinction coefficient.

Moreover, n represents an integer of 1 to 5, and when n is 2 or larger,two or more D² groups present in one molecule may be the same ordifferent.

The alkyl group of D² has the same meaning as the alkyl groupexemplified in R¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkyl group ofD², the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The alkoxy group of D² has the same meaning as the alkyl groupexemplified in D¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkoxy group ofD², the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

R⁶, R⁹, and R¹⁰ each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of R⁶, R⁹, and R¹⁰ has the same meaning as thealkyl group exemplified in R¹ of the above general formula (I) and eachsubstituent which may be possessed also has the same meaning. As thealkyl group of each of R⁶, R⁹, and R¹⁰, the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The aryl group of each of R⁶, R⁹, and R¹⁰ has the same meaning as thearyl group exemplified in R³ of the above general formula (I) and eachsubstituent which may be possessed also has the same meaning. Theheteroaryl group of each of R⁶, R⁹, and R¹⁰ has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I) andeach substituent which may be possessed also has the same meaning.

When the number of carbon atoms of each group falls within anappropriate range, there are cases where the molecular weight does notbecome exceedingly large and the gram extinction coefficient does notget worse.

X represents a nitrogen atom or an optionally substituted methine group.The substituent which may be possessed by the methine group is notparticularly limited but is preferably a halogen atom, a cyano group, ora —COOR⁷ group for obtaining a high solubility in solvents and a highmolar extinction coefficient.

R⁷ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms.

The alkyl group of R⁷ specifically has the same meaning as the alkylgroup exemplified in R¹ of the above general formula (I) and thesubstituent which may be possessed also has the same meaning. As thealkyl group of R⁷, the number of carbon atoms is preferably 1 or more,and the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The aryl group of R⁷ specifically has the same meaning as the aryl groupexemplified in R³ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning as the aryl groupexemplified in R³ of the above general formula (I). The heteroaryl groupof R⁷ specifically has the same meaning as the heteroaryl groupexemplified in R³ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning as the heteroaryl groupexemplified in R³ of the above general formula (I).

The azo compound represented by the above general formula (I) includescompounds represented by the following general formulae (X) and (XI):

in the general formula (X),

R⁸⁰¹ and R⁸⁰² each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms,

D¹³ represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 10 carbon atoms, an optionallysubstituted alkoxy group having 1 to 20 carbon atoms, or a —COOR⁸⁰³group,

e′ represents an integer of 1 to 5, and when e′ is 2 or larger, two ormore D¹³ groups present in one molecule may be the same or different,

R⁸⁰³ represents an optionally substituted alkyl group having 1 to 10carbon atoms,

D¹² represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 10 carbon atoms, an optionallysubstituted alkoxy group having 1 to 10 carbon atoms, or an optionallysubstituted —NHCOR⁸⁰⁴ group,

e represents an integer of 1 to 4, and when e is 2 or larger, two ormore D¹² groups present in one molecule may be the same or different,

R⁸⁰⁴ represents an optionally substituted alkyl group having 1 to 10carbon atoms, an optionally substituted alkoxy group having 1 to 20carbon atoms, or an optionally substituted aryl group having 6 to 20carbon atoms,

X⁴ represents a nitrogen atom or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁸⁰⁵ group as a substituent,

R⁸⁰⁵ represents an optionally substituted alkyl group having 1 to 10carbon atoms,

A⁶ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 10 carbon atoms, anoptionally substituted phenyl group, an optionally substituted alkoxygroup having 1 to 10 carbon atoms, or a —COOR⁸⁰⁶ group, and

R⁸⁰⁶ represents an optionally substituted alkyl group having 1 to 10carbon atoms;

in the general formula (XI),

R⁸¹⁰ and R⁸¹¹ each independently represent an optionally substitutedbranched alkyl group having 1 to 20 carbon atoms,

D¹⁴ represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 10 carbon atoms, an optionallysubstituted alkoxy group having 1 to 10 carbon atoms, or an —NHCOR⁸¹³group,

R⁸¹³ represents an optionally substituted alkyl group having 1 to 10carbon atoms, an optionally substituted alkoxy group having 1 to 20carbon atoms, or an optionally substituted aryl group having 6 to 20carbon atoms,

f represents an integer of 1 to 4, and when f is 2 or larger, two ormore D¹⁴ groups present in one molecule may be the same or different,

A⁷ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 10 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 10 carbon atoms, or a—COOR⁸¹⁴ group,

R⁸¹⁴ represents an optionally substituted alkyl group having 1 to 10carbon atoms,

A⁸ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted alkoxy group having 1 to 20carbon atoms, an optionally substituted alkenyl group having 2 to 20carbon atoms, an optionally substituted alkylcarbonyl group having 1 to20 carbon atoms, an optionally substituted alkoxycarbonyl group having 1to 20 carbon atoms, a formyl group, an R⁸¹⁵OOC(NC)C═CH— group, anNC(NC)C═CH— group, or a group represented by the following generalformula (XII):

R⁸¹⁵ represents an optionally substituted alkyl group having 1 to 20carbon atoms,

D¹⁵ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 20 carbon atoms, or a—COOR⁸¹⁶ group,

f′ represents an integer of 1 to 5, and when f′ is 2 or larger, two ormore D¹⁵ groups present in one molecule may be the same or different,

R⁸¹⁶ represents an optionally substituted alkyl group having 1 to 10carbon atoms,

X⁵ represents a nitrogen atom or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁸¹⁷ group as a substituent, and

R⁸¹⁷ represents an optionally substituted alkyl group having 1 to 10carbon atoms.

In the compound represented by the general formula (X), R⁸⁰¹ and R⁸⁰²represent an optionally substituted alkyl group having 1 to 20 carbonatoms. R⁸⁰¹ and R⁸⁰² preferably have 4 or more carbon atoms and is morepreferably an alkyl group having 5 or more carbon atoms. Moreover, thenumber of carbon atoms is preferably 16 or less, and is more preferably12 or less.

When the number of carbon atoms of the alkyl group is too large, thereare cases where the gram extinction coefficient gets worse since themolecular weight becomes too large. Moreover, at least one of R⁸⁰¹ andR⁸⁰² is preferably a branched alkyl group and further, at least onethereof is preferably a branched alkyl group having 5 to 20 carbonatoms. Furthermore, it is more preferable that both of R⁸⁰¹ and R⁸⁰² area branched alkyl group.

D¹³ represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 10 carbon atoms, an optionallysubstituted alkoxy group having 1 to 20 carbon atoms, or a —COOR⁸⁰³group. Moreover, e′ represents an integer of 1 to 5, and when e′ is 2 orlarger, two or more D¹³ groups present in one molecule may be the sameor different.

In the case where D¹³ is an alkyl group, the number of carbon atoms ispreferably 2 or more and is preferably 8 or less, more preferably 6 orless.

In the case where D¹³ is an alkoxy group, the number of carbon atoms ispreferably 4 or more, more preferably 5 or more. Moreover, the number ofcarbon atoms is preferably 16 or less, more preferably 12 or less.

In the case where D¹³ is a —COOR⁸⁰³ group, R⁸⁰³ represents an optionallysubstituted alkyl group having 1 to 10 carbon atoms. The number ofcarbon atoms of the alkyl group of R⁸⁰³ is preferably 2 or more and ispreferably 8 or less, more preferably 6 or less.

When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

D¹² represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 10 carbon atoms, an optionallysubstituted alkoxy group having 1 to 10 carbon atoms, or an optionallysubstituted —NHCOR⁸⁰⁴ group.

Moreover, e represents an integer of 1 to 4, and when e is 2 or larger,two or more D¹² groups present in one molecule may be the same ordifferent.

The number of carbon atoms of the alkyl group and the alkoxy group ispreferably 1 or more and is preferably 8 or less, more preferably 6 orless.

R⁸⁰⁴ represents an optionally substituted alkyl group having 1 to 10carbon atoms, an optionally substituted alkoxy group having 1 to 20carbon atoms, or an optionally substituted aryl group having 6 to 20carbon atoms. The number of carbon atoms of each of the alkyl and alkoxygroups of R⁸⁰⁴ is preferably 1 or more and is preferably 8 or less, morepreferably 6 or less.

Moreover, the number of carbon atoms of the aryl group of R⁸⁰⁴ ispreferably 6 or more, more preferably 10 or more. Also, the number ofcarbon atoms is preferably 16 or less. When the number of carbon atomsfalls within an appropriate range, there are cases where the compound isexcellent in solubility in solvents and can have a high gram extinctioncoefficient.

X⁴ represents a nitrogen atom or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁸⁰⁵ group as a substituent.

In the case where the methine group has a —COOR⁸⁰⁵ group, R⁸⁰⁵represents an optionally substituted alkyl group having 1 to 10 carbonatoms. The number of carbon atoms of the alkyl group of R⁸⁰⁵ ispreferably 1 or more and is preferably 8 or less, more preferably 6 orless.

When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

A⁶ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 10 carbon atoms, anoptionally substituted phenyl group, an optionally substituted alkoxygroup having 1 to 10 carbon atoms, or a —COOR⁸⁰⁶ group.

Of the alkyl groups and alkoxy groups having 1 to 10 carbon atoms, thenumber of carbon atoms is preferably 1 or more and is preferably 8 orless, more preferably 6 or less.

R⁸⁰⁶ represents a hydrogen atom or an optionally substituted alkyl grouphaving 1 to 10 carbon atoms. The number of carbon atoms of the alkylgroup of R⁸⁰⁶ is preferably 1 or more and is preferably 8 or less, morepreferably 6 or less.

When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

Incidentally, specific examples of the alkyl group in the above generalformula (X) include linear alkyl groups such as methyl, ethyl, propyl,butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl groups;branched alkyl groups such as isopropyl, isobutyl, sec-butyl,tert-butyl, isooctyl, and isononyl groups; cyclic alkyl groups such ascyclopropyl, cyclopentyl, cyclohexyl, and cyclopropylmethyl groups; andthe like.

Moreover, the alkyl group in the above general formula (X) may have anarbitrary substituent. The arbitrary substituent is preferably a lowpolar substituent from the standpoint of solubility in solvents andexamples thereof include halogen atoms such as fluorine, chlorine,bromine, and iodine atoms; alkoxy groups having 1 to 10 carbon atoms,such as methoxy, ethoxy, propoxy, butoxy, isobutoxy, sec-butoxy, andtert-butoxy groups; and the like.

R⁸¹⁰ and R⁸¹¹ in the general formula (XI) represent an optionallysubstituted alkyl group having 1 to 20 carbon atoms. The alkyl group ofR⁸¹⁰ and R⁸¹¹ which may have a substituent includes methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecylgroups; branched alkyl groups such as isopropyl, isobutyl, sec-butyl,tert-butyl, isooctyl, and isononyl groups; cyclic alkyl groups such ascyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopropylmethyl,cyclohexylmethyl, and 4-butylmethylcyclohexyl groups; and the like.

R⁸¹⁰ and R⁸¹¹ have preferably 4 or more carbon atoms, more preferably 5or more carbon atoms. Moreover, the number of carbon atoms is preferably16 or less and more preferably 12 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

Moreover, at least one of R⁸¹⁰ and R⁸¹¹ is preferably a branched alkylgroup and further, at least one thereof is preferably a branched alkylgroup having 5 to 20 carbon atoms. Furthermore, it is more preferablethat both of R⁸¹⁰ and R⁸¹¹ are a branched alkyl group from thestandpoint of solubility.

Specific examples of the substituent which may be optionally possessedby the alkyl groups of each of R⁸¹⁰ and R⁸¹¹ are preferably low polarsubstituents from the standpoint of solubility in solvents, and examplesthereof include halogen atoms such as fluorine, chlorine, bromine, andiodine atoms; alkoxy groups having 1 to 20 carbon atoms, such asmethoxy, ethoxy, propoxy, butoxy, isobutoxy, sec-butoxy, and tert-butoxygroups; alkoxycarbonyl groups having 3 to 20 carbon atoms, such asmethoxycarbonyl, ethoxycarbonyl, and t-butoxycarbonyl groups; a cyanogroup; and the like.

D¹⁴ represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 10 carbon atoms, an optionallysubstituted alkoxy group having 1 to 10 carbon atoms, or an —NHCOR⁸¹³group.

Moreover, f represents an integer of 1 to 4, and when f is 2 or larger,two or more D¹⁴ groups present in one molecule may be the same ordifferent.

The alkyl group of D¹⁴ which may have a substituent has the same meaningas the alkyl group having 1 to 10 carbon atoms, among the alkyl groupshaving 1 to 20 carbon atoms exemplified in R⁸¹⁰.

The alkoxy group of D¹⁴ which may have the substituent includes linearalkoxy groups such as methoxy, ethoxy, propoxy, butoxy, pentyloxy,hexyloxy, heptyloxy, octyloxy, nonyloxy, and decyloxy groups; branchedalkoxy groups such as isopropoxy, isobutoxy, sec-butoxy, tert-butoxy,and isooctyloxy groups; alkoxy groups having a cycloalkane structure,such as cyclopropoxy, cyclopentyloxy, cyclohexyloxy, andcyclopropylmethyloxy groups; and the like.

The number of carbon atoms of each of the alkyl and alkoxy groups of D¹⁴is preferably 8 or less and is more preferably 6 or less since it isadvantageous from the standpoint of the gram extinction coefficient.

Moreover, the substituent which may be possessed by D¹⁴ is preferably alow polar substituent from the standpoint of solubility in solvents.

Specific examples of the substituent which may be possessed by the alkylgroup of D¹⁴ include halogen atoms, alkoxy groups having 1 to 10 carbonatoms, alkoxycarbonyl groups having 3 to 10 carbon atoms, and the like.

Specific examples of the substituent which may be possessed by thealkoxy group of D¹⁴ include halogen atoms, alkyl groups having 1 to 10carbon atoms, carbonyl groups having 1 to 10 carbon atoms such asformyl, acetyl, benzoyl, carbazoyl, and phenylcarbonyl group, and thelike.

R⁸¹³ represents an optionally substituted alkyl group having 1 to 10carbon atoms, an optionally substituted alkoxy group having 1 to 20carbon atoms, or an optionally substituted aryl group having 6 to 20carbon atoms.

The alkyl group of R⁸¹³ has the same meaning as the alkyl groupexemplified in D¹⁴. The number of carbon atoms of alkyl group of R⁸¹³ ispreferably 9 or less and is more preferably 8 or less. The alkoxy groupof R⁸¹³ has the same meaning as the alkoxy group exemplified in A⁸ to bementioned later.

The aryl group of R⁸¹³ is a group obtained by removing one hydrogen atomfrom a monocycle of 5- or 6-membered ring or a condensed ring obtainedby condensing 2 to 4 rings of the monocycles. Specific examples thereofinclude groups of aromatic hydrocarbon ring groups or aromaticheterocyclic groups such as phenyl, tolyl, xylyl, mesityl, naphthyl,thienyl, and pyridyl groups. The number of carbon atoms is preferably 10or more and the number of carbon atoms is preferably 16 or less, morepreferably 12 or less.

Moreover, the substituent which may be possessed by each of the alkyland alkoxy groups of R⁸¹³ has the same meaning as the substituent whichmay be possessed by each of the alkyl and alkoxy groups exemplified inD¹⁴.

The substituent which may be possessed by the aryl group of R⁸¹³includes halogen atoms, alkyl groups having 1 to 20 carbon atoms, alkoxygroups having 1 to 10 carbon atoms, alkoxycarbonyl groups having 1 to 10carbon atoms, and the like.

When the number of carbon atoms of R⁸¹³ falls within an appropriaterange, there are cases where the compound is excellent in solubility insolvents and can have a high gram extinction coefficient.

A⁷ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 10 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 10 carbon atoms, or a—COOR⁸¹⁴ group.

The alkyl group and alkoxy group of A⁷ have the same meaning as thealkyl group and alkoxy group exemplified in D¹⁴. In the alkyl group andalkoxy group having 1 to 10 carbon atoms, the number of carbon atoms ispreferably 8 or less and is more preferably 6 or less.

The aryl group of A⁷ has the same meaning as the aryl group exemplifiedin R⁸¹³. Of the group, it is preferably an optionally substituted phenylgroup.

R⁸¹⁴ represents an optionally substituted alkyl group having 1 to 10carbon atoms. The alkyl group of R⁸¹⁴ has the same meaning as the alkylgroup exemplified in D¹⁴. Of the group, the number of carbon atoms ispreferably 8 or less and is more preferably 6 or less. When the numberof carbon atoms of each of A⁷ and R⁸¹⁴ falls within an appropriaterange, there are cases where the compound is excellent in solubility insolvents and can have a high gram extinction coefficient.

Moreover, the substituent which may be possessed by each of the alkylgroup of A⁷ and the alkyl group of R⁸¹⁴ has the same meaning as thesubstituent which may be possessed by the alkyl group exemplified inD¹⁴. The substituent which may be possessed by the alkoxy group of A⁷has the same meaning as the substituent which may be possessed by thealkoxy group exemplified in D¹⁴, and the substituent which may bepossessed by the aryl group of A⁷ has the same meaning as thesubstituent which may be possessed by the aryl group exemplified inR⁸¹³.

A⁸ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted alkoxy group having 1 to 20carbon atoms, an optionally substituted alkenyl group having 2 to 20carbon atoms, an optionally substituted alkylcarbonyl group having 1 to20 carbon atoms, an optionally substituted alkoxycarbonyl group having 1to 20 carbon atoms, a formyl group, an R⁸¹⁵OOC(NC)C═CH— group, anNC(NC)C═CH— group, or a group represented by the following generalformula (XII).

The alkyl group of A⁸ has the same meaning as the alkyl groupexemplified in R⁸¹⁰. The number of carbon atoms is preferably 3 or more.Moreover, the number of carbon atoms is preferably 18 or less and ismore preferably 16 or less.

In the alkenyl group of A⁸, the position of the carbon-carbonunsaturated bond is not particularly limited and the alkenyl group mayhave a plurality of unsaturated bonds. Also, the group may be linear orbranched and may have an arbitrary substituent. The alkenyl groupincludes a vinyl group, a propenyl group, a hexenyl group, and the like.Of these, the alkenyl group preferably has 3 or more carbon atoms.Moreover, the number of carbon atoms is preferably 16 or less, morepreferably 12 or less.

The alkoxy group of A⁸ includes linear, branched, and cyclic alkoxygroups having 1 to 20 carbon atoms, such as phenoxy, naphthyloxy,dodecanoxy, toxymethyl, methoxyethyl, methoxybutyl, ethoxybutyl,ethoxyethyl, and ethoxybutyl in addition to those having the samemeaning as the alkoxy group exemplified in D¹⁴; and the like Of these,the alkoxy group preferably has 3 or more carbon atoms. Moreover, thenumber of carbon atoms is preferably 16 or less, more preferably 12 orless.

The alkyl group contained in the alkoxycarbonyl group of A⁸ includesthose having the same meaning as the alkyl group exemplified in R⁸¹⁰.The number of carbon atoms is preferably 1 or more. Moreover, the numberof carbon atoms is preferably 18 or less and is more preferably 16 orless.

The alkoxy group contained in the alkoxycarbonyl group of A⁸ includesthose having the same meaning as the alkoxy group exemplified in A⁸. Thenumber of carbon atoms is preferably 1 or more. Moreover, the number ofcarbon atoms is preferably 18 or less and is more preferably 16 or less.

When the number of carbon atoms of A⁸ falls within an appropriate range,there are cases where the compound is excellent in solubility insolvents and can have a high gram extinction coefficient.

R⁸¹⁵ represents an optionally substituted alkyl group having 1 to 20carbon atoms. The alkyl group of A⁸¹⁵ includes those having the samemeaning as the alkyl group exemplified in R⁸¹⁰. The number of carbonatoms of A⁸¹⁵ is preferably 2 or more, more preferably 4 or more.Moreover, the number of carbon atoms is preferably 18 or less and ismore preferably 16 or less. When the number of carbon atoms falls withinan appropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

Moreover, the substituent which may be possessed by the alkyl group ofeach of A⁸ and R⁸¹⁵ has the same meaning as the substituent which may bepossessed by the alkyl group exemplified in R⁸¹⁰. Specific examples ofthe substituent which may be possessed by the alkoxy group of A⁸ includehalogen atoms, alkoxy groups having 1 to 20 carbon atoms, alkyl groupshaving 1 to 20 carbon atoms, carbonyl groups having 1 to 20 carbonatoms, such as formyl, acetyl, benzoyl, carbazoyl, and phenylcarbonylgroups, and the like.

Specific examples of the substituent which may be possessed by thealkylcarbonyl group of A⁸ include alkoxy groups having 1 to 20 carbonatoms, and specific examples of the substituent which may be possessedby the alkenyl group of A⁸ include alkyl groups having 1 to 20 carbonatoms, alkoxy groups having 1 to 20 carbon atoms, alkoxycarbonyl groupshaving 2 to 20 carbon atoms, and the like.

D¹⁵ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 20 carbon atoms, or a—COOR⁸¹⁶ group.

Moreover, f′ represents an integer of 1 to 5, and when f′ is 2 orlarger, two or more D¹⁵ groups present in one molecule may be the sameor different.

The alkyl group of D¹⁵ includes those having the same meaning as thealkyl group exemplified in R⁸¹⁰. Of these, the alkyl group preferablyhas 3 or more carbon atoms. Moreover, the number of carbon atoms ispreferably 18 or less, more preferably 16 or less.

The alkoxy group of D¹⁵ includes those having the same meaning as thealkoxy group exemplified in A⁸. Of these, the alkyl group preferably has4 or more carbon atoms, more preferably 5 or more carbon atoms.Moreover, the number of carbon atoms is preferably 16 or less, morepreferably 12 or less.

R⁸¹⁶ is an optionally substituted alkyl group having 1 to 10 carbonatoms and specifically, includes those having the same meaning as thealkyl group exemplified in D¹⁴. Of these, the alkyl group preferably has2 or more carbon atoms. Moreover, the number of carbon atoms ispreferably 8 or less, more preferably 6 or less.

When the number of carbon atoms of each group falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

Moreover, the substituent which may be possessed by the alkyl group ofD¹⁵ has the same meaning as the substituent which may be possessed bythe alkyl group exemplified in R⁸¹⁰, and the substituent which may bepossessed by the alkoxy group of D¹⁵ has the same meaning as thesubstituent which may be possessed by the alkoxy group exemplified inA⁸. The substituent which may be possessed by the alkyl group of R⁸¹⁶has the same meaning as the substituent which may be possessed by thealkyl group exemplified in D¹⁴.

X⁵ represents a nitrogen atom or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁸¹⁷ group as a substituent.

The alkyl group having 1 to 10 carbon atoms of R⁸¹⁷ which may have asubstituent and the substituent which may be possessed by the alkylgroup have the same meaning as the alkyl group and the substituent whichmay be possessed by the alkyl group, which are exemplified in D¹⁴. Ofthese, the number of carbon atoms is preferably 8 or less, morepreferably 6 or less. When the number of carbon atoms of each groupfalls within an appropriate range, there are cases where the compound isexcellent in solubility in solvents and can have a high gram extinctioncoefficient.

Specific examples of the azo compound represented by the above generalformula (I) are exemplified in the following. The invention is notlimited to these unless it exceeds the gist thereof.

The use of the compounds represented by the following general formulae(VIII) and (IX) as azo compounds of the invention is more preferablesince the solubility in solvents can be improved.

wherein

R⁶⁰¹ and R⁶⁰² each independently represent an optionally substitutedbranched alkyl group having 7 to 20 carbon atoms,

D⁹ represents a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, an —NHCOR⁶⁰³ group, or an—NHSO₂R⁶⁰⁸ group,

R⁶⁰³ and R⁶⁰⁸ each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms,

a represents an integer of 1 to 4, and when a is 2 or larger, two ormore D⁹ groups present in one molecule may be the same or different,

A³ represents a halogen atom, a cyano group, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, an optionally substituted heteroarylgroup having 2 to 20 carbon atoms, an optionally substituted alkoxygroup having 1 to 20 carbon atoms, or a —COOR⁶⁰⁴ group,

R⁶⁰⁴ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms,

A⁴ represents a halogen atom, an optionally substituted alkyl grouphaving 1 to 20 carbon atoms, an optionally substituted alkenyl grouphaving 2 to 20 carbon atoms, an optionally substituted alkylcarbonylgroup having 2 to 20 carbon atoms, an optionally substitutedalkoxycarbonyl group having 2 to 20 carbon atoms, a formyl group, anR⁶⁰⁵OOC(NC)C═CH— group, or an NC(NC)C═CH— group,

R⁶⁰⁵ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms,

X² represents a nitrogen atom or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁶⁰⁷ group, and

R⁶⁰⁷ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms.

wherein

R⁷⁰¹ and R⁷⁰² each independently represent an optionally substitutedbranched alkyl group having 5 to 20 carbon atoms,

D¹¹ represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted alkoxy group having 1 to 20 carbon atoms, an —NHCOR⁷⁰³group, or an —NHSO₂R⁷⁰⁸ group,

R⁷⁰³ and R⁷⁰⁸ each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms,

d represents an integer of 1 to 4, and when d is 2 or larger, two ormore D¹¹ groups present in one molecule may be the same or different,

A⁵ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, anoptionally substituted heteroaryl group having 2 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 20 carbon atoms, or a—COOR⁷⁰⁴ group,

R⁷⁰⁴ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms,

D¹⁰ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 20 carbon atoms, a—COOR⁷⁰⁶ group, a —COR⁷⁰⁹ group, or an —OCOR⁷¹⁰ group,

b represents an integer of 1 to 5, and when b is 2 or larger, two ormore D¹⁰ groups present in one molecule may be the same or different,

R⁷⁰⁶, R⁷⁰⁹, and R⁷¹⁰ each independently represent an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, or an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms,

X³ represents a nitrogen atom or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁷⁰⁷ group, and

R⁷⁰⁷ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms.

In the compounds represented by the general formulae (VIII) and (IX),R⁶⁰¹ and R⁶⁰² each independently represent an optionally substitutedbranched alkyl group having 7 to 20 carbon atoms and R⁷⁰¹ and R⁷⁰² eachindependently represent an optionally substituted branched alkyl grouphaving 5 to 20 carbon atoms.

The alkyl group of each of R⁶⁰¹ and R⁶⁰² specifically has the samemeaning as the branched alkyl group having 7 or more carbon atoms, amongthe alkyl groups exemplified in R¹ of the above general formula (I) andeach substituent which may be possessed also has the same meaning.Moreover, the alkyl group of each of R⁷⁰¹ and R⁷⁰² specifically has thesame meaning as the branched alkyl group having 5 or more carbon atoms,among the alkyl groups exemplified in R¹ of the above general formula(I) and each substituent which may be possessed also has the samemeaning.

As the alkyl group of each of R⁶⁰¹ and R⁶⁰², the number of carbon atomsis preferably 7 or more, preferably 8 or more and the number of carbonatoms is preferably 18 or less, more preferably 16 or less.

As the alkyl group of each of R⁷⁰¹ and R⁷⁰², the number of carbon atomsis preferably 5 or more, preferably 6 or more and the number of carbonatoms is preferably 18 or less, more preferably 16 or less.

When the number of carbon atoms of each of R⁶⁰¹, R⁶⁰², R⁷⁰¹, and R⁷⁰²falls within an appropriate range, there are cases where the compound isexcellent in solubility in solvents and can have a high gram extinctioncoefficient.

D⁹ represents a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, an —NHCOR⁶⁰³ group, or an—NHSO₂R⁶⁰⁸ group,

D¹¹ represents a hydrogen atom, a halogen atom, an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted alkoxy group having 1 to 20 carbon atoms, an —NHCOR⁷⁰³group, or an —NHSO₂R⁷⁰⁸ group,

The alkyl group of each of D⁹ and D¹¹ specifically has the same meaningas the alkyl group exemplified in R¹ of the above general formula (I)and each substituent which may be possessed also has the same meaning.As the alkyl group of each of D⁹ and D¹¹, the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The alkoxy group of each of D⁹ and D¹¹ specifically has the same meaningas the alkoxy group exemplified in D¹ of the above general formula (I)and each substituent which may be possessed also has the same meaning.As the alkoxy group of each of D⁹ and D¹¹, the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

R⁶⁰³ and R⁶⁰⁸ each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms, and R⁷⁰³ and R⁷⁰⁸ eachindependently represent an optionally substituted alkyl group having 1to 20 carbon atoms, an optionally substituted aryl group having 6 to 20carbon atoms, or an optionally substituted heteroaryl group having 2 to20 carbon atoms.

The alkyl group of each of R⁶⁰³ and R⁶⁰⁸ specifically has the samemeaning as the alkyl group exemplified in R¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkyl group of each of R⁶⁰³ and R⁶⁰⁸, the number ofcarbon atoms is preferably 1 or more and the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The aryl group of each of R⁶⁰³ and R⁶⁰⁸ specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I). The heteroaryl group of each of R⁶⁰³ and R⁶⁰⁸ specifically has thesame meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

a represents an integer of 1 to 4, and when a is 2 or larger, two ormore D⁹ groups present in one molecule may be the same or different, andd represents an integer of 1 to 4, and when d is 2 or larger, two ormore D¹¹ groups present in one molecule may be the same or different.

A³ represents a halogen atom, a cyano group, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, an optionally substituted heteroarylgroup having 2 to 20 carbon atoms, an optionally substituted alkoxygroup having 1 to 20 carbon atoms, or a —COOR⁶⁰⁴ group, and A⁵represents a hydrogen atom, a halogen atom, a cyano group, an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms, an optionallysubstituted alkoxy group having 1 to 20 carbon atoms, or a —COOR⁷⁰⁴group.

The alkyl group of each of A³ and A⁵ specifically has the same meaningas the alkyl group exemplified in R¹ of the above general formula (I)and each substituent which may be possessed also has the same meaning.As the alkyl group of each of A³ and A⁵, the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The alkoxy group of each of A³ and A⁵ specifically has the same meaningas the alkoxy group exemplified in D¹ of the above general formula (I)and each substituent which may be possessed also has the same meaning.As the alkoxy group of each of A³ and A⁵, the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The aryl group of each of A³ and A⁵ has the same meaning as the arylgroup exemplified in R³ of the above general formula (I) and eachsubstituent which may be possessed also has the same meaning as the arylgroup exemplified in R³ of the above general formula (I).

As the aryl group of each of A³ and A⁵, for the reason of highsolubility in solvents, an optionally substituted phenyl group ornaphthyl group is preferable. As the substituent which may be possessedby the phenyl group or the naphthyl group, for the reason of highsolubility in solvents, a halogen atom, an optionally substituted alkylgroup having 1 to 10 carbon atoms, or an optionally substituted alkoxygroup having 1 to 10 carbon atoms is preferable.

The heteroaryl group of each of A³ and A⁵ has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I) andeach substituent which may be possessed also has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I). Asthe heteroaryl group of each of A³ and A⁵, for the reason of highsolubility in solvents, an optionally substituted thienyl group ispreferable. As the substituent which may be possessed by the thienylgroup, for the reason of high solubility in solvents, a halogen atom, anoptionally substituted alkyl group having 1 to 10 carbon atoms, or anoptionally substituted alkoxy group having 1 to 10 carbon atoms ispreferable.

R⁶⁰⁴ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms, and R⁷⁰⁴ represents an optionally substituted alkyl grouphaving 1 to 20 carbon atoms, an optionally substituted aryl group having6 to 20 carbon atoms, or an optionally substituted heteroaryl grouphaving 2 to 20 carbon atoms.

The alkyl group of each of R⁶⁰⁴ and R⁷⁰⁴ specifically has the samemeaning as the alkyl group exemplified in R¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkyl group of each of R⁶⁰⁴ and R⁷⁰⁴, the number ofcarbon atoms is preferably 16 or less, more preferably 10 or less,particularly preferably 6 or less. When the number of carbon atoms fallswithin an appropriate range, there are cases where the compound isexcellent in solubility in solvents and can have a high gram extinctioncoefficient.

The aryl group of each of R⁶⁰⁴ and R⁷⁰⁴ specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I).

The heteroaryl group of each of R⁶⁰⁴ and R⁷⁰⁴ specifically has the samemeaning as the heteroaryl group exemplified in R³ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

X² represents a nitrogen atom or a methine group which may have ahalogen atom, a cyano group, or a —COOR⁶⁰⁷ group, and X³ represents anitrogen atom or a methine group which may have a halogen atom, a cyanogroup, or a —COOR⁷⁰⁷ group.

Moreover, R⁶⁰⁷ represents an optionally substituted alkyl group having 1to 20 carbon atoms, an optionally substituted aryl group having 6 to 20carbon atoms, or an optionally substituted heteroaryl group having 2 to20 carbon atoms, and R⁷⁰⁷ represents an optionally substituted alkylgroup having 1 to 20 carbon atoms, an optionally substituted aryl grouphaving 6 to 20 carbon atoms, or an optionally substituted heteroarylgroup having 2 to 20 carbon atoms.

The alkyl group of each of X² and X³ specifically has the same meaningas the alkyl group exemplified in R¹ of the above general formula (I)and each substituent which may be possessed also has the same meaning.As the alkyl group of each of X² and X³, the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The aryl group of each of X² and X³ specifically has the same meaning asthe aryl group exemplified in R³ of the above general formula (I) andeach substituent which may be possessed also has the same meaning as thearyl group exemplified in R³ of the above general formula (I).

The heteroaryl group of each of X² and X³ specifically has the samemeaning as the heteroaryl group exemplified in R³ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

A⁴ represents a halogen atom, an optionally substituted alkyl grouphaving 1 to 20 carbon atoms, an optionally substituted alkenyl grouphaving 2 to 20 carbon atoms, an optionally substituted alkylcarbonylgroup having 2 to 20 carbon atoms, an optionally substitutedalkoxycarbonyl group having 2 to 20 carbon atoms, a formyl group, anR⁶⁰⁵OOC(NC)C═CH— group, or an NC(NC)C═CH— group, and R⁶⁰⁵ represents anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of A⁴ and R⁶⁰⁵ specifically has the same meaningas the alkyl group exemplified in R¹ of the above general formula (I)and each substituent which may be possessed also has the same meaning.

As the alkyl group of each of A⁴ and R⁶⁰⁵, the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The alkenyl group of A⁴ specifically has the same meaning as the alkenylgroup exemplified in A² of the above general formula (I) and thesubstituent which may be possessed also has the same meaning. Of thegroup, the alkenyl group preferably has 3 or more carbon atoms.Moreover, the number of carbon atoms is preferably 16 or less, morepreferably 12 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The alkylcarbonyl group of A⁴ specifically has the same meaning as thealkylcarbonyl group exemplified in A² of the above general formula (I)and the substituent which may be possessed also has the same meaning.The number of carbon atoms of the alkyl group in the alkylcarbonyl groupof A⁴ preferably has 1 or more carbon atoms and the number of carbonatoms is preferably 18 or less, more preferably 16 or less.

The alkoxycarbonyl group of A⁴ specifically has the same meaning as thealkoxycarbonyl group exemplified in A² of the above general formula (I)and the substituent which may be possessed also has the same meaning.The number of carbon atoms of the alkyl group in the alkoxycarbonylgroup of A⁴ preferably has 1 or more carbon atoms and the number ofcarbon atoms is preferably 18 or less, more preferably 16 or less.

When the number of carbon atoms of A⁴ falls within an appropriate range,there are cases where the compound is excellent in solubility insolvents and can have a high gram extinction coefficient.

The aryl group of R⁶⁰⁵ specifically has the same meaning as the arylgroup exemplified in R³ of the above general formula (I) and thesubstituent which may be possessed also has the same meaning as the arylgroup exemplified in R³ of the above general formula (I).

The heteroaryl group of R⁶⁰⁵ specifically has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I) andthe substituent which may be possessed also has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I).

D¹⁰ represents a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 20 carbon atoms, a—COOR⁷⁰⁶ group, a —COR⁷⁰⁹ group, or a —OCOR⁷¹⁰ group.

Moreover, R⁷⁰⁶, R⁷⁰⁹, and R⁷¹⁰ each independently represent anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of D¹⁰, R⁷⁰⁶, R⁷⁰⁹, and R⁷¹⁰ specifically hasthe same meaning as the alkyl group exemplified in R¹ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning. As the alkyl group of each of D¹⁰, R⁷⁰⁶, R⁷⁰⁹, andR⁷¹⁰, the number of carbon atoms is preferably 16 or less, morepreferably 10 or less, particularly preferably 6 or less. When thenumber of carbon atoms falls within an appropriate range, there arecases where the compound is excellent in solubility in solvents and canhave a high gram extinction coefficient.

The alkoxy group of D¹⁰ has the same meaning as the alkoxy groupexemplified in D¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkoxy group ofD¹⁰, the number of carbon atoms is preferably 16 or less, morepreferably 10 or less, particularly preferably 6 or less. When thenumber of carbon atoms falls within an appropriate range, there arecases where the compound is excellent in solubility in solvents and canhave a high gram extinction coefficient.

The aryl group of each of R⁷⁰⁶, R⁷⁰⁹, and R⁷¹⁰ specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I).

The heteroaryl group of each of R⁷⁰⁶, R⁷⁰⁹, and R⁷¹⁰ specifically hasthe same meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

With regard to the azo compound of the invention, the molecular weightthereof is preferably 3,000 or less, more preferably 1,500 or less,including substituent(s) in the case where the compound has thesubstituent(s). Also, the molecular weight is preferably 400 or more,more preferably 500 or more. When the molecular weight falls within anappropriate range, there are cases where a good gram extinctioncoefficient can be obtained.

The compounds represented by the general formulae (I) and (VIII) to (XI)can be synthesized, for example, in accordance with the methodsdescribed in JP-A-3-256793.

The azo compound of the invention is characterized by having excellentsolubility in solvents, in particular, in a solvent having a relativepermittivity of 3 or less, as measured at a frequency of 1 kHz and at22° C. and a solubility in water of 20 mg/L or less at 25° C. The azocompound of the invention has a solubility in n-decane of generally1×10⁻² mol·L⁻¹ or more, preferably 3×10⁻² mol·L⁻¹ or more, morepreferably 5×10⁻² mol·L⁻¹ or more. The higher the solubility is, themore the compound is preferred. However, the solubility thereof isgenerally about 2 mol·L⁻¹ or less. When the solubility is higher than aspecific value, there are cases where it becomes possible to displaydisplay devices such as a display.

In the case where the azo compound of the invention is to be used inelectrowetting displays, it is desirable that the compound should bewater-insoluble, in view of the principle thereof. The term“water-insoluble” herein means that the solubility in water under theconditions of 25° C. and 1 atm is 0.1% by mass or less, preferably 0.01%by mass or less.

Moreover, the molar extinction coefficient is preferably 10,000(L·mol⁻¹·cm⁻¹) or more, and is more preferably 40,000 (L·mol⁻¹·cm⁻¹) ormore for satisfying the performance of a display device.

Furthermore, the value of the product of the molar extinctioncoefficient ε (L·mol⁻¹·cm⁻¹) of n-decane solution of the azo compound ofthe invention at the absorption-maximum wavelength and the saturatedconcentration C (mol·L⁻¹) of the azo compound in n-decane at 5° C., εC,is preferably 1,000 cm⁻¹ or more, more preferably 2,000 cm⁻¹ or more.The more the value of εC is, the more the compound is preferred sincethe coloration degree becomes high. Although there is no particularupper limit thereon, the value is generally 100,000 cm⁻¹ or less.

With respect to the concentration of the azo compound in the ink of theinvention, the ink is prepared so as to have any desired concentrationin accordance with the intended use thereof. For example, in the casewhere the compound is to be used as a colorant for electrowettingdisplays, the compound is used after being diluted with a solvent to aconcentration of generally 1% by mass or more in accordance with thedesired value of εC. However, the concentration thereof is preferably 3%by mass or more, more preferably 5% by mass or more. Also, theconcentration is usually about 80% by mass or less.

The ink of the invention may contain the above azo compound alone or maycontain two or more thereof in any combination and ratio.

Since the azo compound of the invention is excellent in solubility insolvents and has a high extinction coefficient, the compound is usefulas a material for an optical shutter, a display material, in particular,an electrowetting display material or an electrophoretic displaymaterial.

There is no particular lower limit on the viscosity of the ink of theinvention which has a temperature of 25° C. However, usually theviscosity is preferably 0.1 mPa·s or more. Meanwhile, the upper limitthereof is preferably 10,000 mPa·s or less, more preferably 1,000 mPa·sor less, particularly preferably 100 mPa·s or less. When the ink has anappropriate viscosity, there are cases where the operation of thedisplay device becomes good.

With respect to the relative permittivity and viscosity of the solventin the invention and those of the ink containing the solvent, thecolorant, and the like, the difference between the solvent and the inkin to values thereof is preferably smaller, because influences on theoperation characteristics in the case of use in display devices or thelike are lessened.

Consequently, although the ink of the invention may contain anyadditives suitable for each application according to need within therange where the effects of the invention are not impaired, it ispreferable that the properties of the solvent should be kept unchanged.

(Other Compounds)

The above azo compound may be used alone in the ink of the invention orthe ink may contain other compound(s) in order to obtain a desired colortone. For example, it is possible to mix a plurality of coloredcompounds such as yellow, red, blue, purple, and orange compounds withthe azo compound of the invention to render the ink black or othercolor.

Other compounds which may be contained in the ink of the invention canbe selected at will from compounds which have solubility ordispersibility in the medium to be used in the invention, so long as theselected compounds do not impair the effects of the invention.

In the case where the ink of the invention is to be used inelectrowetting displays, any compounds can be selected and used as othercompounds. Examples thereof include nitroso compounds, nitro compounds,monoazo compounds, disazo compounds, trisazo compounds, polyazocompounds, stilbene compounds, carotenoid compounds, diarylmethanecompounds, triarylmethane compounds, xanthene compounds, acridinecompounds, quinoline compounds, methine compounds, thiazole compounds,isothiazole compounds, indamine compounds, indophenol compounds, azinecompounds, oxazine compounds, thiazine compounds, heterocycliccompounds, sulfide dyes, lactone compounds, hydroxyketone compounds,aminoketone compounds, anthraquinone compounds, indigo compounds,phthalocyanine compounds, pyrazole-based compounds, cyanovinylcompounds, natural dyes, oxidation dyes, inorganic pigments, metalcomplexes, carbon black, and the like.

Specific examples thereof include: Oil Blue N (alkylamine-substitutedanthraquinone), Solvent Green, Solvent Blue, Sudan Blue, Sudan Red,Sudan Yellow, Sudan Black, Disperse Violet, Disperse Red, Disperse Blue,and Disperse Yellow; the compounds described in InternationalPublication WO2009/063880; and the compounds described in InternationalPublication WO2010/031860. These compounds themselves are known and areavailable as commercial products.

In particular, the ink according to the invention preferably contains atleast one selected from the group consisting of heterocyclic compounds,cyanovinyl compounds, and anthraquinone compounds. A preferred eachcolored ink such as a black ink can be rendered possible by using thesecompounds in any desired combination.

Specific examples of the heterocyclic compounds are not particularlylimited but at least one compound selected from the group consisting ofthe following general formulae (III) to (V) is preferred.

As the heterocyclic compound, a compound represented by the followinggeneral formula (III) is mentioned:

wherein

R¹⁰¹, R¹⁰², D³ and D⁴ each independently represent an arbitrarysubstituent,

e represents an integer of 1 to 5, and when e is 2 or larger, two ormore D³ groups present in one molecule may be the same or different, and

g represents an integer of 1 to 4, and when g is 2 or larger, two ormore D⁴ groups present in one molecule may be the same or different.

In the general formula (III), R¹⁰¹ and R¹⁰² each independently representan arbitrary substituent.

R¹⁰¹ is not particularly limited so long as it does not impair theeffects of the invention but is preferably an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, an optionally substituted heteroarylgroup having 2 to 20 carbon atoms, a —COOR¹⁰³ group, an —NR¹⁰⁷R¹⁰⁸group, or a —COR¹¹² group, for a high solubility in solvents and a highextinction coefficient.

Also, R¹⁰² is not particularly limited so long as it does not impair theeffects of the invention but is preferably an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms, for a high solubility insolvents and a high extinction coefficient.

R¹⁰³ and R¹¹² each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms, and R¹⁰⁷ and R¹⁰⁸ eachindependently represent a hydrogen atom, an optionally substituted alkylgroup having 1 to 20 carbon atoms, an optionally substituted aryl grouphaving 6 to 20 carbon atoms, or an optionally substituted heteroarylgroup having 2 to 20 carbon atoms.

The alkyl group of each of R¹⁰¹, R¹⁰², R¹⁰³, R¹⁰⁷, R¹⁰⁸, and R¹¹²specifically has the same meaning as the alkyl group exemplified in R¹of the above general formula (I) and each substituent which may bepossessed also has the same meaning. As the alkyl group of each of R¹⁰²,R¹⁰³, R¹⁰⁷, R¹⁰⁸, and R¹¹², the number of carbon atoms is preferably 16or less, more preferably 10 or less, particularly preferably 6 or less.When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

The aryl group of each of R¹⁰¹, R¹⁰², R¹⁰³, R¹⁰⁷, R¹⁰⁸, and R¹¹²specifically has the same meaning as the aryl group exemplified in R³ ofthe above general formula (I) and each substituent which may bepossessed also has the same meaning as the aryl group exemplified in R³of the above general formula (I).

The heteroaryl group of each of R¹⁰¹, R¹⁰², R¹⁰³, R¹⁰⁷, R¹⁰⁸, and R¹¹²specifically has the same meaning as the heteroaryl group exemplified inR³ of the above general formula (I) and each substituent which may bepossessed also has the same meaning as the heteroaryl group exemplifiedin R³ of the above general formula (I).

D³ represents an arbitrary substituent and is not particularly limitedso long as it does not impair the effects of the invention but ispreferably a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, a cyano group, a hydroxygroup, a —COOR¹⁰⁴ group, an —NHCOR¹⁰⁹ group, an —NHSO₂R¹¹⁰ group, a—COR¹¹³ group, or an —OCOR¹¹⁵ group, for a high solubility in solventsand a high extinction coefficient.

Moreover, e represents an integer of 1 to 5, and when e is 2 or larger,two or more D³ groups present in one molecule may be the same ordifferent.

R¹⁰⁴, R¹⁰⁹, R¹¹⁰, R¹¹³, and R¹¹⁵ each independently represent anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of D³, R¹⁰⁴, R¹⁰⁹, R¹¹⁰, R¹¹³, and R¹¹⁵specifically has the same meaning as the alkyl group exemplified in R¹of the above general formula (I) and each substituent which may bepossessed also has the same meaning. As the alkyl group of each of D³,R¹⁰⁴, R¹⁰⁹, R¹¹⁰, R¹¹³, and R¹¹⁵, the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The alkoxy group of D³ has the same meaning as the alkoxy groupexemplified in D¹ of the above general formula (I) and each substituentwhich may be possessed also has the same meaning. As the alkoxy group ofD³, the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The aryl group of each of R¹⁰⁴, R¹⁰⁹, R¹¹⁰, R¹¹³, and R¹¹⁵ specificallyhas the same meaning as the aryl group exemplified in R³ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning as the aryl group exemplified in R³ of the abovegeneral formula (I).

The heteroaryl group of each of R¹⁰⁴, R¹⁰⁹, R¹¹⁰, R¹¹³, and R¹¹⁵specifically has the same meaning as the heteroaryl group exemplified inR³ of the above general formula (I) and each substituent which may bepossessed also has the same meaning as the heteroaryl group exemplifiedin R³ of the above general formula (I).

D⁴ represents an arbitrary substituent and is not particularly limitedso long as it does not impair the effects of the invention but ispreferably a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, a cyano group, a —COOR¹⁰⁵group, an —NHCOR¹⁰⁶ group, an —NHSO₂R¹¹¹ group, or a —COR¹¹⁴ group, fora high solubility in solvents and a high extinction coefficient.

g represents an integer of 1 to 4, and when g is 2 or larger, two ormore D⁴ groups present in one molecule may be the same or different.

R¹⁰⁵, R¹⁰⁶, R¹¹¹, and R¹¹⁴ each independently represent an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, or an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of D⁴, R¹⁰⁵, R¹⁰⁶, R¹¹¹, and R¹¹⁴ specificallyhas the same meaning as the alkyl group exemplified in R¹ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning. As the alkyl group of each of D⁴, R¹⁰⁵, R¹⁰⁶, R¹¹¹,and R¹¹⁴, the number of carbon atoms is preferably 16 or less, morepreferably 10 or less, particularly preferably 6 or less. When thenumber of carbon atoms falls within an appropriate range, there arecases where the compound is excellent in solubility in solvents and canhave a high gram extinction coefficient.

The alkoxy group of D⁴ has the same meaning as the alkoxy groupexemplified in D¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. In the alkoxy group ofD⁴, the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The aryl group of each of R¹⁰⁵, R¹⁰⁶, R¹¹¹, and R¹¹⁴ specifically hasthe same meaning as the aryl group exemplified in R³ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning as the aryl group exemplified in R³ of the abovegeneral formula (I).

The heteroaryl group of each of R¹⁰⁵, R¹⁰⁶, R¹¹¹, and R¹¹⁰ specificallyhas the same meaning as the heteroaryl group exemplified in R³ of theabove general formula (I) and each substituent which may be possessedalso has the same meaning as the heteroaryl group exemplified in R³ ofthe above general formula (I).

Specific examples of the compound represented by the above generalformula (III) are shown in the following. The invention is not limitedto these unless it exceeds the gist thereof.

The compound represented by general formula (III) can be synthesized,for example, by the methods described in International PublicationWO2009/063880.

As the heterocyclic compound, a compound represented by the followinggeneral formula (IV) may be mentioned:

wherein

R²⁰¹, R²⁰², R²⁰³, R²⁰⁴, R²⁰⁵, R²⁰⁶, R²⁰⁷, and R²⁰⁸ each independentlyrepresent an arbitrary substituent and

Z represents a nitrogen atom or an optionally substituted methine group.

R²⁰¹ represents an arbitrary substituent. R²⁰¹ is not particularlylimited so long as it does not impair the effects of the invention butis preferably a hydrogen atom or an optionally substituted alkyl grouphaving 1 to 20 carbon atoms, for a high extinction coefficient.

The alkyl group having 1 to 20 carbon atoms of R²⁰¹ which may have asubstituent has the same meaning as the alkyl group exemplified in R¹ ofthe above general formula (I) and the substituent which may be possessedalso has the same meaning. Moreover, R²⁰¹ may be combined with Z to forma cyclic structure.

R²⁰¹ is preferably a substituent having a small molecular weight fromthe viewpoint of the gram extinction coefficient. Specifically, thenumber of carbon atoms is preferably 16 or less, more preferably 10 orless, particularly preferably 6 or less. When the number of carbon atomsfalls within an appropriate range, there are cases where the compound isexcellent in solubility in solvents and can have a high gram extinctioncoefficient.

Moreover, R²⁰¹ is preferably an unsubstituted alkyl group from theviewpoint of production and is particularly preferably an unsubstitutedalkyl group having 1 to 4 carbon atoms, such as methyl, ethyl, propyl,isopropyl, or butyl group.

R²⁰² represents an arbitrary substituent. R²⁰² is not particularlylimited so long as it does not impair the effects of the invention butis preferably a cyano group or a —COOR²⁰⁹ group, for a high solubilityin solvents and a high extinction coefficient.

R²⁰⁹ represents an optionally substituted alkyl group having 1 to 20carbon atoms, an optionally substituted aryl group having 6 to 20 carbonatoms, or an optionally substituted heteroaryl group having 2 to 20carbon atoms.

The alkyl group of R²⁰⁹ specifically has the same meaning as the alkylgroup exemplified in R¹ of the above general formula (I) and thesubstituent which may be possessed also has the same meaning. As thealkyl group of R²⁰⁹, the number of carbon atoms is preferably 16 orless, more preferably 10 or less, particularly preferably 6 or less.When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

The aryl group of R²⁰⁹ specifically has the same meaning as the arylgroup exemplified in R³ of the above general formula (I) and thesubstituent which may be possessed also has the same meaning as the arylgroup exemplified in R³ of the above general formula (I).

The heteroaryl group of R²⁰⁹ specifically has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I) andthe substituent which may be possessed also has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I).

R²⁰³ and R²⁰⁴ represent an arbitrary substituent. R²⁰³ and R²⁰⁴ are notparticularly limited so long as they do not impair the effects of theinvention but are each independently preferably an optionallysubstituted alkyl group having 1 to 20 carbon atoms, for a highsolubility in solvents and a high extinction coefficient.

R²⁰³ and R²⁰⁴ may be combined each other to form a cyclic structure.Also, R²⁰³ and R²⁰⁴ may be combined with R²⁰⁶ and R²⁰⁷, respectively, toform a cyclic structure.

The alkyl group of each of R²⁰³ and R²⁰⁴ specifically has the samemeaning as the alkyl group exemplified in R¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkyl group of each of R²⁰³ and R²⁰⁴, the number ofcarbon atoms is preferably 2 or more, more preferably 4 or more. Also,the number of carbon atoms is preferably 16 or less, more preferably 10or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

R²⁰⁵, R²⁰⁶, R²⁰⁷, and R²⁰⁸ each independently represent an arbitrarysubstituent. R²⁰⁵, R²⁰⁶, R²⁰⁷, and R²⁰⁸ are not particularly limited solong as they do not impair the effects of the invention but arepreferably, a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, an —NHCOR²¹⁰ group, or an—NHSO₂R²¹² group, for a high solubility in solvents and a highextinction coefficient.

R²¹⁰ and R²¹² each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of R²⁰⁵, R²⁰⁶, R²⁰⁷, R²⁰⁸, R²¹⁰, and R²¹²specifically has the same meaning as the alkyl group exemplified in R¹of the above general formula (I) and each substituent which may bepossessed also has the same meaning. As the alkyl group of each of R²⁰⁵,R²⁰⁶, R²⁰⁷, R²⁰⁸, R²¹⁰, and R²¹², the number of carbon atoms ispreferably 16 or less, more preferably 10 or less, particularlypreferably 6 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The alkoxy group of each of R²⁰⁵, R²⁰⁶, R²⁰⁷, and R²⁰⁸ has the samemeaning as the alkoxy group exemplified in D¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkoxy group of each of R²⁰⁵, R²⁰⁶, R²⁰⁷, and R²⁰⁸,the number of carbon atoms is preferably 16 or less, more preferably 10or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

Furthermore, R²⁰⁵, R²⁰⁶, R²⁰⁷, and R²⁰⁸ are each independentlypreferably an alkyl group having 1 to 4 carbon atoms, such as methyl,ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl, sec-butyl, ortert-butyl group, an —NHCOR²¹⁰ group, or an —NHSO₂R²¹² group, and areparticularly preferably methyl, an —NHCOR²¹⁰ group, or an —NHSO₂R²¹²group, from the standpoints of high solubility in solvents and gramextinction coefficient.

The aryl group of each of R²¹⁰ and R²¹² specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I).

The heteroaryl group of R²¹⁰ and R²¹² specifically has the same meaningas the heteroaryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the heteroaryl group exemplified in R³ of the above generalformula (I).

Z represents a nitrogen atom or an optionally substituted methine group.In the case where Z is a methine group, Z may be unsubstituted oroptionally substituted but the substituent which may be possessed by Zincludes an optionally substituted alkyl group having 1 to 10 carbonatoms, a —COOR²¹¹ group, and the like.

R²¹¹ represents an optionally substituted alkyl group having 1 to 20carbon atoms. The alkyl group of R²¹¹ specifically has the same meaningas the alkyl group exemplified in R¹ of the above general formula (I)and the substituent which may be possessed also has the same meaning. Asthe alkyl group of R²¹¹, the number of carbon atoms is preferably 16 orless, more preferably 10 or less, particularly preferably 6 or less.

When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

Z is preferably a nitrogen atom, a methine group, a methine groupsubstituted with an alkyl group having 1 to 4 carbon atoms, or a methinegroup substituted with an alkoxycarbonyl group having 2 to 5 carbonatoms.

As particularly preferable compounds among the compounds represented bythe above general formula (IV), compounds shown in the following Tables1 to 3 may be mentioned.

TABLE 1 No. Z R²⁰¹ R²⁰² R²⁰³  1 N CH₂CH₃ CN i-C₄H₉  2 N CH₃ CNCH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃  3 C—CO₂CH₂CH₃ CH₃ CO₂CH₂CH₃CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃  4 N CH₂CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃  5 NCH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃  6 C—CO₂CH₂CH₃ CH₃ CO₂CH₂CH₃CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃  7 C—CO₂CH₂CH₃ CH₃ CO₂CH₂CH₃CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃  8 N CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃  9 N CH₃CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 10 N CH₂CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 11N CH₂CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 12 N n-C₄H₉ CN i-C₄H₉ 13 N n-C₄H₉CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 14 N i-C₃H₇ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 15N CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 16 N CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃17 N CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 18 C—CO₂CH₂CH₃ CH₃ CO₂CH₂CH₃i-C₄H₉ 19 C—CO₂CH₂CH₃ CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 20 C—CO₂CH₂CH₃CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ No. R²⁰⁴ R²⁰⁵ R²⁰⁶ R²⁰⁷ R²⁰⁸  1 i-C₄H₉NHCOCH₃ H H H  2 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃ H H H  3CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃ H H H  4 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃H H H  5 n-C₈H₁₇ CH₃ H H H  6 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃ H H H  7CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₂CH₃ H H H  8 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃CH₂CH₃ H H H  9 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₂CH₃ H H H 10CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃ H H H 11 CH₂CH₃ NHCOCH₃ H H H 12i-C₄H₉ NHCOCH₃ H H H 13 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃ H H H 14CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃ H H H 15 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ i-C₃H₇H H H 16 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃ OCH₃ H H 17CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ H H H H 18 i-C₄H₉ CH₃ H H H 19CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃ OCH₃ H H 20 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃CH₂CH₃ H H H

TABLE 2 No. Z R²⁰¹ R²⁰² R²⁰³ 21 N i-C₃H₇ CN i-C₄H₉ 22 N CH₃ CO₂CH₃CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 23 N CH₃ CO₂-n-C₃H₇ i-C₄H₉ 24 N CH₃ CN(CF₂)₅CF₃ 25 N CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 26 N CH₃ CN i-C₄H₉ 27 NCH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 28 C—CO₂CH₃ CH₃ CO₂CH₃CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 29 C—CO₂-n-C₄H₉ CH₃ CO₂-n-C₄H₉ i-C₄H₉ 30 C—CH₃CH₃ CO₂CH₃ CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 31 C-n-C₄H₉ CH₃ CO₂CH₃ i-C₄H₉ 32C—CO₂—CH₂CH₃ CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 33 C—CO₂—CH₂CH₃ CH₃CO₂—CH₂CH₃ CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 34 C—CO₂—CH₂CH₃ CH₃ CO₂—CH₂CH₃CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 35 C—CO₂—CH₂CH₃ CH₃ CNCH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 36 C—CN CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 37C—CN CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 38 N CH₃ CNCH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 39 N CH₃ CN CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 40C—CO₂CH₃ CH₃ CO₂CH₃ CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ No. R²⁰⁴ R²⁰⁵ R²⁰⁶ R²⁰⁷R²⁰⁸ 21 i-C₄H₉ H H H H 22 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃ H H H 23i-C₄H₉ NHCOCH₃ H H H 24 (CF₂)₅CF₃ NHCOCH₃ H H H 25CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOPh H H H 26 i-C₄H₉ NHCO-i-C₄H₉ H H H 27CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃ OCH₃ H H 28 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃Cl H CH₃ H 29 i-C₄H₉ NHCOCH₃ CH₃ H H 30 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃ HOCH₃ H 31 i-C₄H₉ NHCO-i-C₄H₉ H H H 32 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃H H H 33 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃ OCH₃ H H 34CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃ OCH₃ H H 35 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃H H H 36 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃ H H H 37CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ CH₃ H H H 38 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ NHCOCH₃Cl H H 39 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ F H H H 40 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃Cl CH₃ H H

TABLE 3 No. Z R²⁰¹ R²⁰² R²⁰³ 41 N n-C₆H₁₃ CO₂-n-C₄H₉ n-C₆H₁₃ 42 NCH₂OCH₂CH₃ CO₂CF₃ CH₂OCH₂CH₃ 43 N CF₃ CO₂—Ph CF₃ 44 N CF₂CF₃ CO₂CH₂—PhCF₂CF₃ 45 N Ph CO₂CH₂-cyclohexane Ph 46 N CH₂—Ph CO₂CH₂CH₂OCH₃ CH₂—Ph 47N CH₂CH₂O—Ph CO₂-n-C₈H₁₇ CH₂CH₂O—Ph 48 N CH₂-cyclohexane CO₂CH₂CH₂CH₂CF₃CH₂-cyclohexane 49 N n-C₈H₁₇ CO₂CH₂CH₂CH₂CN n-C₈H₁₇ 50 N CH₃ CNCH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃ 51 C—CO₂Ph n-C₆H₁₃ CO₂-n-C₄H₉ n-C₆H₁₃ 52C—CO₂CH₂Ph CH₂OCH₂CH₃ CO₂CF₃ CH₂OCH₂CH₃ 53 C—CO₂-n-C₈H₁₇ CF₃ CO₂—Ph CF₃54 C—CO₂-n-C₆H₁₃ CF₂CF₃ CO₂CH₂—Ph CF₂CF₃ 55 C—CO₂-cyclohaxne PhCO₂CH₂-cyclohexane Ph 56 C—CN CH₂—Ph CO₂CH₂CH₂OCH₃ CH₂—Ph 57 C—CNCH₂CH₂O—Ph CO₂-n-C₈H₁₇ CH₂CH₂O—Ph 58 C—CN CH₂-cyclohexaneCO₂CH₂CH₂CH₂CF₃ CH₂-cyclohexane 59 C—CN n-C₈H₁₇ CO₂CH₂CH₂CH₂CN n-C₈H₁₇60 C—CN CH₂CH₂CH₂CF₃ CO₂CH₂(CH₃)CH₂CH₃ CH₂CH₂CH₂CF₃ No. R²⁰⁴ R²⁰⁵ R²⁰⁶R²⁰⁷ R²⁰⁸ 41 n-C₆H₁₃ O-n-Bu H H H 42 CH₂OCH₂CH₃ CF₃ H H H 43 CF₃NHSO₂CF₃ H H H 44 CF₂CF₃ NHSO₂-n-Bu H H H 45 Ph Br H H H 46 CH₂—Ph HO-n-C₆H₁₃ H H 47 CH₂CH₂O—Ph H CF₂CF₂CF₂CF₃ H H 48 CH₂-cyclohexane HNHSO₂CH₂—Ph H H 49 n-C₈H₁₇ H NHSO₂—Ph H H 50 CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃NHSO₂-n-Bu H H H 51 n-C₆H₁₃ O-n-Bu H H H 52 CH₂OCH₂CH₃ CF₃ H H H 53 CF₃NHSO₂CF₃ H H H 54 CF₂CF₃ NHSO₂-n-Bu H H H 55 Ph Br H H H 56 CH₂—Ph HO-n-C₆H₁₃ H H 57 CH₂CH₂O—Ph H CF₂CF₂CF₂CF₃ H H 58 CH₂-cyclohexane HNHSO₂CH₂—Ph H H 59 n-C₈H₁₇ H NHSO₂—Ph H H 60 CH₂CH₂CH₂CF₃ Me H Me H

The compound represented by general formula (IV) can be synthesized, forexample, in accordance with the methods described in JP-A-8-505820.

As the heterocyclic compound, a compound represented by the followinggeneral formula (V) may be mentioned:

wherein

R³⁰¹, R³⁰², D⁵, and D⁶ each independently represent an arbitrarysubstituent,

l represents an integer of 1 to 4, and when 1 is 2 or larger, two ormore D⁵ groups present in one molecule may be the same or different, and

j represents an integer of 1 to 4, and when j is 2 or larger, two ormore D⁶ groups present in one molecule may be the same or different.

R³⁰¹ and R³⁰² each independently represent an arbitrary substituent.R³⁰¹ and R³⁰² are not particularly limited so long as they do not impairthe effects of the invention but are preferably, an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, or an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms, for a highextinction coefficient and a high solubility in solvents.

The alkyl group of each of R³⁰¹ and R³⁰² specifically has the samemeaning as the alkyl group exemplified in R¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkyl group of each of R³⁰¹ and R³⁰², the number ofcarbon atoms is preferably 2 or more, more preferably 4 or more. Also,the number of carbon atoms is preferably 16 or less, more preferably 12or less. When the number of carbon atoms falls within an appropriaterange, there are cases where the compound is excellent in solubility insolvents and can have a high gram extinction coefficient.

The aryl group of each of R³⁰¹ and R³⁰² specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I).

The heteroaryl group of each of R³⁰¹ and R³⁰² specifically has the samemeaning as the heteroaryl group exemplified in R³ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

D⁵ represents an arbitrary substituent. D⁵ is not particularly limitedso long as it does not impair the effects of the invention but ispreferably, a hydrogen atom, a halogen atom, a cyano group, anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted alkoxy group having 1 to 20 carbon atoms, an —SCNgroup, a —COOR³⁰³ group, a —COR³⁰⁶ group, or an —OCOR³⁰⁷ group, for ahigh extinction coefficient and a high solubility in solvents.

l represents an integer of 1 to 4, and when 1 is 2 or larger, two ormore D⁵ groups present in one molecule may be the same or different.

Moreover, R³⁰³, R³⁰⁶, and R³⁰⁷ each independently represent anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of D⁵, R³⁰³, R³⁰⁶, and R³⁰⁷ specifically has thesame meaning as the alkyl group exemplified in R¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkyl group of each of D⁵, R³⁰³, R³⁰⁶, and R³⁰⁷,the number of carbon atoms is preferably 16 or less, more preferably 10or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The alkoxy group of D⁵ has the same meaning as the alkoxy groupexemplified in D¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkoxy group ofeach of D⁵ and R³⁰⁶ the number of carbon atoms is preferably 16 or less,more preferably 10 or less, particularly preferably 6 or less. When thenumber of carbon atoms falls within an appropriate range, there arecases where the compound is excellent in solubility in solvents and canhave a high gram extinction coefficient.

The aryl group of each of R³⁰³, R³⁰⁶, and R³⁰⁷ specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I).

The heteroaryl group of each of R³⁰³, R³⁰⁶, and R³⁰⁷ specifically hasthe same meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

D⁶ represents an arbitrary substituent. D⁶ is not particularly limitedso long as it does not impair the effects of the invention but ispreferably, a hydrogen atom, an optionally substituted alkyl grouphaving 1 to 20 carbon atoms, an optionally substituted alkoxy grouphaving 1 to 20 carbon atoms, an —NHCOR³⁰⁴ group, or an —NHSO₂R³⁰⁵ group,for a high solubility in solvents and a high extinction coefficient.

j represents an integer of 1 to 4, and when j is 2 or larger, two ormore D⁶ groups present in one molecule may be the same or different.

Moreover, R³⁰⁴ and R³⁰⁵ each independently represent an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, or an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of D⁶, R³⁰⁴, and R³⁰⁵ specifically has the samemeaning as the alkyl group exemplified in R¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkyl group of each of D⁶, R³⁰⁴, and R³⁰⁵, thenumber of carbon atoms is preferably 16 or less, more preferably 10 orless, particularly preferably 6 or less. When the number of carbon atomsfalls within an appropriate range, there are cases where the compound isexcellent in solubility in solvents and can have a high gram extinctioncoefficient.

The alkoxy group of D⁶ has the same meaning as the alkoxy groupexemplified in D¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkoxy group ofD⁶, the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The aryl group of each of R³⁰⁴ and R³⁰⁵ specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I).

The heteroaryl group of each of R³⁰⁴ and R³⁰⁵ specifically has the samemeaning as the heteroaryl group exemplified in R³ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

Specific examples of the compound represented by the above generalformula (V) are shown in the following but are not limited to theseunless they exceed the gist thereof.

The cyclic compound represented by the general formula (V) can besynthesized, for example, in accordance with the methods described inJP-A-10-204307 and JP-A-2000-280635.

With regard to the heterocyclic compounds represented by the generalformulae (III) to (V) and the like as described above, from thestandpoint of the gram extinction coefficient, the molecular weightthereof is generally 2,000 or less, preferably 1,000 or less, includingsubstituent(s) in the case where the compound has the substituent(s).Also, the molecular weight is generally 300 or more, preferably 400 ormore.

Specific examples of the cyanovinyl compound are not particularlylimited but a compound represented by the following general formula (VI)is preferable.

wherein

R⁴⁰¹, R⁴⁰², R⁴⁰³, R⁴⁰⁴, and D⁷ each independently represent an arbitrarysubstituent and

r represents an integer of 1 to 4, and when r is 2 or larger, two ormore D⁷ groups present in one molecule may be the same or different.

R⁴⁰¹ and R⁴⁰² each independently represent an arbitrary substituent.R⁴⁰¹ and R⁴⁰² are not particularly limited so long as they do not impairthe effects of the invention but are each independently preferably anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms, fora high extinction coefficient and a high solubility in solvents.

The alkyl group of each of R⁴⁰¹ and R⁴⁰² specifically has the samemeaning as the alkyl group exemplified in R¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkyl group of each of R⁴⁰¹ and R⁴⁰², the number ofcarbon atoms is preferably 2 or more, more preferably 4 or more. Also,the number of carbon atoms is preferably 16 or less, more preferably 12or less. When the number of carbon atoms falls within an appropriaterange, there are cases where the compound is excellent in solubility insolvents and can have a high gram extinction coefficient.

The aryl group of each of R⁴⁰¹ and R⁴⁰² specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I).

The heteroaryl group of each of R⁴⁰¹ and R⁴⁰² specifically has the samemeaning as the heteroaryl group exemplified in R³ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

R⁴⁰³ and R⁴⁰⁴ each independently represent an arbitrary substituent.R⁴⁰³ and R⁴⁰⁴ are not particularly limited so long as they do not impairthe effects of the invention but R⁴⁰³ is preferably a hydrogen atom or acyano group and R⁴⁰⁴ is preferably a cyano group or a —COR⁴⁰⁵ group, fora high extinction coefficient and a high solubility.

Moreover, R⁴⁰⁵ represents an optionally substituted alkyl group having 1to 20 carbon atoms, an optionally substituted alkoxy group having 1 to20 carbon atoms, an optionally substituted aryl group having 6 to 20carbon atoms, or an optionally substituted heteroaryl group having 2 to20 carbon atoms.

The alkyl group of R⁴⁰⁵ specifically has the same meaning as the alkylgroup exemplified in R¹ of the above general formula (I) and thesubstituent which may be possessed also has the same meaning. As thealkyl group of R⁴⁰⁵, the number of carbon atoms is preferably 16 orless, more preferably 10 or less, particularly preferably 6 or less.When the number of carbon atoms falls within an appropriate range, thereare cases where the compound is excellent in solubility in solvents andcan have a high gram extinction coefficient.

The alkoxy group of R⁴⁰⁵ has the same meaning as the alkoxy groupexemplified in D¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkoxy group ofR⁴⁰⁵, the number of carbon atoms is preferably 16 or less, morepreferably 10 or less, particularly preferably 6 or less. When thenumber of carbon atoms falls within an appropriate range, there arecases where the compound is excellent in solubility in solvents and canhave a high gram extinction coefficient.

The aryl group of R⁴⁰⁵ specifically has the same meaning as the arylgroup exemplified in R³ of the above general formula (I) and thesubstituent which may be possessed also has the same meaning as the arylgroup exemplified in R³ of the above general formula (I).

The heteroaryl group of R⁴⁰⁵ specifically has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I) andthe substituent which may be possessed also has the same meaning as theheteroaryl group exemplified in R³ of the above general formula (I).

D⁷ represents an arbitrary substituent. D⁷ is not particularly limitedso long as it does not impair the effects of the invention but ispreferably, a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, an —NHCOR⁴⁰⁶ group, or an—NHSO₂R⁴⁰⁷ group, for a high extinction coefficient and a highsolubility in solvents.

r represents an integer of 1 to 4, and when r is 2 or larger, two ormore D⁷ groups present in one molecule may be the same or different.

Moreover, R⁴⁰⁶ and R⁴⁰⁷ each independently represent an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, or an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of D⁷, R⁴⁰⁶, and R⁴⁰⁷ specifically has the samemeaning as the alkyl group exemplified in R¹ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning. As the alkyl group of each of D⁷, R⁴⁰⁶, and R⁴⁰⁷, thenumber of carbon atoms is preferably 2 or more, more preferably 4 ormore. Also, the number of carbon atoms is preferably 16 or less, morepreferably 12 or less. When the number of carbon atoms falls within anappropriate range, there are cases where the compound is excellent insolubility in solvents and can have a high gram extinction coefficient.

The alkoxy group of D⁷ has the same meaning as the alkoxy groupexemplified in D¹ of the above general formula (I) and the substituentwhich may be possessed also has the same meaning. As the alkoxy group ofD⁷, the number of carbon atoms is preferably 16 or less, more preferably10 or less, particularly preferably 6 or less. When the number of carbonatoms falls within an appropriate range, there are cases where thecompound is excellent in solubility in solvents and can have a high gramextinction coefficient.

The aryl group of each of R⁴⁰⁶ and R⁴⁰⁷ specifically has the samemeaning as the aryl group exemplified in R³ of the above general formula(I) and each substituent which may be possessed also has the samemeaning as the aryl group exemplified in R³ of the above general formula(I).

The heteroaryl group of each of R⁴⁰⁶ and R⁴⁰⁷ specifically has the samemeaning as the heteroaryl group exemplified in R³ of the above generalformula (I) and each substituent which may be possessed also has thesame meaning as the heteroaryl group exemplified in R³ of the abovegeneral formula (I).

Specific examples of the cyanovinyl compound represented by the abovegeneral formula (VI) are shown in the following but are not limited tothese unless they exceed the gist thereof.

The compound represented by the above general formula (VI) can besynthesized, for example, in accordance with the methods described inJP-A-11-100523 and JP-A-2000-247942.

Specific examples of the anthraquinone compound are not particularlylimited but a compound represented by the following general formula(VII) is preferable.

wherein

D⁸ each independently represent an arbitrary substituent, and trepresents an integer of 1 to 8 and, when t is 2 or larger, two or moreD⁸ groups present in one molecule may be the same or different.

D⁸ represents an arbitrary substituent. D⁸ is not particularly limitedso long as it does not impair the effects of the invention but ispreferably, a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, a cyano group, a hydroxygroup, an amino group, a nitro group, a —COOR⁵⁰¹ group, an —NHR⁵⁰²group, an —NHCOR⁵⁰³ group, or an —SR⁵⁰⁴ group, for a high extinctioncoefficient and a high solubility in solvents.

t represents an integer of 1 to 8, and when t is 2 or larger, two ormore D⁸ groups present in one molecule may be the same or different.

Moreover, R⁵⁰¹, R⁵⁰², R⁵⁰³, and R⁵⁰⁴ each independently represent anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms.

The alkyl group of each of D⁸, R⁵⁰¹, R⁵⁰², R⁵⁰³, and R⁵⁰⁴ specificallyhas the same meaning as the alkyl group exemplified in R¹ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning. As the alkyl group of each of D⁸, R⁵⁰¹, R⁵⁰², R⁵⁰³,and R⁵⁰⁴, the number of carbon atoms is preferably 16 or less, morepreferably 10 or less, particularly preferably 6 or less. When thenumber of carbon atoms falls within an appropriate range, there arecases where the compound is excellent in solubility in solvents and canhave a high gram extinction coefficient.

The aryl group of each of R⁵⁰¹, R⁵⁰², R⁵⁰³, and R⁵⁰⁴ specifically hasthe same meaning as the aryl group exemplified in R³ of the abovegeneral formula (I) and each substituent which may be possessed also hasthe same meaning as the aryl group exemplified in R³ of the abovegeneral formula (I). As the aryl group of each of R⁵⁰² and R⁵⁰⁴, for thereason of high solubility in solvents, an optionally substituted phenylgroup or naphthyl group is preferable.

As the substituent which may be possessed by the phenyl group or thenaphthyl group, for the reason of high solubility in solvents, a halogenatom, an optionally substituted alkyl group having 1 to 10 carbon atoms,or an optionally substituted alkoxy group having 1 to 10 carbon atoms ispreferable.

The heteroaryl group of each of R⁵⁰¹, R⁵⁰², R⁵⁰³, and R⁵⁰⁴ specificallyhas the same meaning as the heteroaryl group exemplified in R³ of theabove general formula (I) and each substituent which may be possessedalso has the same meaning as the heteroaryl group exemplified in R³ ofthe above general formula (I).

Specific examples of the anthraquinone compound represented by the abovegeneral formula (VII) are shown in the following but are not limited tothese unless they exceed the gist thereof.

The anthraquinone compound represented by the above general formula(VII) can be synthesized, for example, in accordance with the methodsdescribed in U.S. Pat. No. 5,558,808 and JP-T-11-506151.

With regard to the anthraquinone compounds represented by the generalformula (VII), from the standpoint of gram extinction coefficient, themolecular weight thereof is generally 2,000 or less, preferably 1,000 orless, including substituent(s) in the case where the compound has thesubstituent(s). Also, the molecular weight is generally 300 or more,preferably 400 or more.

With regard to the concentration of the compounds represented by theabove general formulae (I) to (VII) in the ink containing the compounds,the ink is prepared in arbitrary concentration depending on the usepurpose thereof. In the case where the compounds are used as compoundsfor electrowetting displays, the compounds are used in a concentrationof 0.2% by mass or more after dilution with a solvent depending on anecessary εC value but the concentration is preferably 1% by mass ormore, more preferably 5% by mass or more. Also, the concentration isusually preferably about 80% by mass or less.

In the case where the ink of the invention is used as a black ink, it ispreferable to contain at least one of the compounds represented by theformulae (III) to (VII) in addition to the compound represented by theabove general formula (I). Inclusion of these compounds makes itpossible to attain a high light absorption in a wide wavelength rangewithin the visible light region. Use of these compounds is superior inthat even when these compounds are used as a mixture thereof, thesolubility thereof in solvents does not decrease and the mixture show ahigh solubility.

Furthermore, the ink of the invention may contain any additives suitablefor each application according to need within the range where theeffects of the invention are not impaired.

Hue of each ink can be quantitatively evaluated in the CIE color spacechromaticity coordinates L*a*b*. L* represents lightness; L*=0 indicateblack and L*=100 indicate white, in terms of diffuse color. a*b*represents hue, and chroma is represented by C* that is determined byC*=√(a^(*2)+b^(*2)) from a*b*. The value of C* indicates the following:the closer to 0 the value is, the more the color is achromatic.

Incidentally, in the case where hue of a black ink is evaluated, in themeasurement by a spectrophotometer, it is necessary to reduce opticalpath length for measurement for obtaining suitable transmitted lightintensity in the case of an ink having an extremely high blackness. Inthis case, since the transmitted light increases when the optical pathlength for measurement is reduced, the value of lightness L* to bemeasured apparently increases. Therefore, in the case where the valuesof L* measured in cells different in the optical path length formeasurement are compared, it is necessary to note that actual blacknessis sometimes higher than the apparent L* in the ink measured in a cellhaving a small optical path length for measurement.

In the case where the ink of the invention is used as a black ink, theink shows a preferable hue since the values of L* and C* are close to 0.When measured using a cell having an optical path length for measurementof 0.004 mm, C* is preferably 20 or less, more preferably 10 or less.There is no lower limit thereon and a value closer to 0 is preferable.Moreover, when similarly measured using a cell having an optical pathlength for measurement of 0.004 mm, the value of L* is preferably 20 orless, preferably 15 or less. There is no lower limit thereon and a valuecloser to 0 is preferable.

(Applications)

The ink of the invention is suitably used as an ink for displays. As thedisplays, the ink is especially useful in a display which has a displaypart containing an ink and in which an image is displayed by controllingvoltage application to the display part, a display in which an image isdisplayed by changing a colored state by means of voltage application,and a display in which an image is displayed further usingelectrophoretic particles or an aqueous medium in the display part.

As the display in which an image is displayed by changing a coloredstate by means of voltage application, for example, there may bementioned one in which the color is changed and the image is displayedthrough movement, such as development or aggregation, of a colored orcolorless ink or a solvent by means of voltage application but thedisplay is not limited thereto.

The electrophoretic particles are charged particles and may have acolor. Multiple kinds of electrophoretic particles may be contained inthe display part. Meanwhile, the aqueous medium is a fluid which mayhave a color, and the display part may have multiple kinds of aqueousmedia. The aqueous medium includes water, non-charged liquids, liquidshaving an affinity for water, and liquids which are akin to water insurface tension. Examples thereof include alcohols, liquids whichcontain an inorganic salt, e.g., an alkali metal halide, and the like.

Furthermore, the azo compound and ink of the invention are particularlyuseful as inks for use in electrowetting type displays orelectrophoresis type displays.

It is also possible to provide a satisfactory ink having an excellenthue, such as black, by combining the azo compound of the invention withother compound(s). For example, the black ink is useful also as a memberwhich functions as an optical shutter.

Although usable in any display device which has a display, the ink ofthe invention is especially useful in electronic paper.

Examples of display technologies include the electrowetting system andthe electrophoretic system. Applications of such displays includevarious displays for computers, for electronic paper, and for electronicinks. There is a possibility that such displays might be capable ofreplacing most of the current liquid-crystal display applications. Ofthese, it is especially preferred to use the ink of the invention as anink for electrowetting displays.

EXAMPLES

The invention will be explained below in more detail with reference toExamples and Comparative Examples, but the invention should not beconstrued as being limited to the following Examples.

<Synthesis of Intermediate M-1

After 4-n-butylaniline (8.02 g, 54 mmol) and an aqueous 7% hydrochloricacid solution (80 ml) were stirred and cooled with ice, an aqueoussolution containing sodium nitrite (3.76 g, 55 mmol) dissolved in 25 mlof water was added dropwise thereto and the whole was stirred to form adiazo solution. Into another vessel were introduced2-amino-3-cyanothiophene (6.68 g, 54 mmol) and methanol (100 ml), andthen the diazo solution was added dropwise thereto on an ice bath toachieve coupling. The formed precipitate was taken out by filtration anddried to obtain M-1 (14 g, yield 92%).

<Synthesis of Intermediate M-2

After 4-n-amylaniline (10.0 g, 61 mmol) and an aqueous 7% hydrochloricacid solution (100 ml) were stirred and cooled with ice, an aqueoussolution containing sodium nitrite (4.23 g, 61 mmol) dissolved in water(40 ml) was added dropwise thereto and the whole was stirred to form adiazo solution. Into another vessel were introduced2-amino-3-cyanothiophene (7.60 g, 61 mmol) and methanol (120 ml), andthen the diazo solution was added dropwise thereto on an ice bath toachieve coupling. The formed precipitate was taken out by filtration anddried to obtain M-2 (18.3 g, yield 100%).

<Synthesis of Intermediate M-3

After isobutyl 4-aminobenzoate (5.00 g, 26 mmol) and an aqueous 7%hydrochloric acid solution (50 ml) were stirred and cooled with ice, anaqueous solution containing sodium nitrite (1.78 g, 26 mmol) dissolvedin water (20 ml) was added dropwise thereto and the whole was stirred toform a diazo solution. Into another vessel were introduced2-amino-3-cyanothiophene (3.21 g, 26 mmol) and methanol (60 ml), andthen the diazo solution was added dropwise thereto on an ice bath toachieve coupling. The formed precipitate was taken out by filtration anddried to obtain M-3 (8.50 g, yield 100%).

<Synthesis of Intermediate M-4

After (2-ethyl)hexyl 4-aminobenzoate (6.22 g, 25 mmol) and an aqueous 7%hydrochloric acid solution (39 ml) were stirred and cooled with ice, anaqueous solution containing sodium nitrite (1.74 g, 25 mmol) dissolvedin water (12 ml) was added dropwise thereto and the whole was stirred toform a diazo solution. Into another vessel were introduced2-amino-3-cyanothiophene (2.86 g, 23 mmol) and methanol (50 ml), andthen the diazo solution was added dropwise thereto on an ice bath toachieve coupling. The formed precipitate was taken out by filtration anddried to obtain M-4 (6.04 g, yield 63%).

<Synthesis of Intermediate M-5

4-Butoxyaniline (5.0 g, 30 mmol) was dissolved in 7% hydrochloric acid(50 ml) and the whole was cooled on an ice bath. Then, an aqueoussolution (10 ml) of sodium nitrite (2.2 g, 32 mmol) was added dropwisethereto while keeping the internal temperature at 0 to 2° C. and thewhole was stirred at the same temperature for 60 minutes to obtain adiazo solution. Into another vessel were placed 2-amino-4-methylthiazole(3.5 g, 30 ml), methanol (60 ml), and urea (0.18 g), and then the diazosolution was added dropwise thereto under cooling with an ice bath whilekeeping the internal temperature at 5° C. or lower. The mixture wasneutralized with sodium acetate, water was added thereto, insolublematter was taken out by filtration and washed with a mixed solvent ofmethanol/water=9/1 (volume ratio) and methanol, sequentially, to obtainthe intermediate M-5 (7.69 g).

<Synthesis of Intermediate C-1

A mixture of m-aminoacetanilide (13.0 g, 87 mmol), N,N-dimethylformamide(60 ml), 1-bromo-2-ethylhexane (50.4 g, 261 mmol), and potassiumcarbonate (49.5 g, 358 mmol) was stirred at 140° C. for 14 hours. Afterbeing allowed to cool, the mixture was filtered and water was added tothe filtrate, followed by extraction with toluene.

The resulting organic layer was concentrated and then purified by silicagel column chromatography to obtain C-1 (17.4 g, yield 54%).

<Synthesis of Intermediate C-2

A mixture of 3-ethylaniline (10.0 g, 83 mmol), N,N-dimethylformamide (50ml), 1-bromo-2-ethylhexane (47.8 g, 248 mmol), and potassium carbonate(45.6 g, 330 mmol) was stirred at 110° C. for 24 hours. After beingallowed to cool, the mixture was filtered and water was added to thefiltrate, followed by extraction with toluene. The resulting organiclayer was concentrated and then purified by silica gel columnchromatography to obtain C-2 (6.3 g, yield 22%).

<Synthesis of Intermediate C-3

A mixture of 3-isopropylaniline (10.0 g, 74 mmol), N,N-dimethylformamide(50 ml), 1-bromo-2-ethylhexane (42.8 g, 220 mmol), and potassiumcarbonate (40.9 g, 300 mmol) was stirred at 140° C. for 20 hours. Afterbeing allowed to cool, the mixture was filtered and water was added tothe filtrate, followed by extraction with toluene. The resulting organiclayer was concentrated and then purified by silica gel columnchromatography to obtain C-3 (8.56 g, yield 32%).

<Synthesis of Intermediate C-4

A mixture of 3′-amino-4′-methoxyacetanilide (25.0 g, 139 mmol),N,N-dimethylformamide (125 ml), 1-bromo-2-ethylhexane (80.4 g, 416mmol), and potassium carbonate (76.7 g, 554 mmol) was stirred at 140° C.for 14 hours. After being allowed to cool, the mixture was filtered andwater was added to the filtrate, followed by extraction with toluene.The resulting organic layer was concentrated and then purified by silicagel column chromatography to obtain C-4 (9.82 g, yield 18%).

<Synthesis of Intermediate C-5

A mixture of m-toluidine (51.1 g, 477 mmol), 1-bromo-2-ethylhexane(357.3 g, 1.86 mol), and potassium carbonate (221.5 g, 1.6 mol) wasstirred at 140° C. for 17 hours. After being allowed to cool, themixture was filtered and the resulting organic layer was concentratedand then purified by silica gel column chromatography to obtain C-5 (52g, yield 33%).

<Synthesis of Intermediate C-6

A mixture of 2-methoxy-5-methylaniline (25.3 g, 184 mmol),N,N-dimethylformamide (100 ml), 1-bromo-2-ethylhexane (145.2 g, 752mmol), and potassium carbonate (90.1 g, 652 mmol) was stirred at 130° C.for 6 hours. After being allowed to cool, the mixture was filtered andwater was added to the filtrate, followed by extraction with toluene.The resulting organic layer was concentrated and then purified by silicagel column chromatography to obtain C-6 (11.76 g, yield 18%).

<Synthesis of Intermediate C-7

Under ice cooling, 2-ethylhexanoyl chloride (19 ml, 111 mmol) was addeddropwise to a mixture of 1,3-phenylenediamine (10 g, 93 mmol),tetrahydrofuran (THF) (125 ml), and triethylamine (30 ml, 231 mmol).After the reaction mixture was filtered, the resulting filtrate wasconcentrated and then purified by silica gel column chromatography. Amixture of the resulting monoamide compound (10.0 g), dimethylformamide(50 ml), 1-bromo-2-ethylhexane (21 ml, 120 mmol), and potassiumcarbonate (22 g, 160 mmol) was stirred at 140° C. for 24 hours. Afterbeing allowed to cool, the mixture was filtered and water was added tothe filtrate, followed by extraction with toluene. The resulting organiclayer was concentrated and then purified by silica gel columnchromatography to obtain C-7 (5.2 g, yield 27%).

<Synthesis of Intermediate C-8

A mixture of the intermediate C-3 (5.0 g, 12.4 mmol), methanol (10 ml),desalted water (30 ml), and 35% hydrochloric acid (3 ml) was stirred at60° C. for 3 hours. After 35% hydrochloric acid (3 ml) was additionallyadded thereto, the mixture was further stirred at 60° C. for 3 hours.After 35% hydrochloric acid (1 ml) was additionally added thereto, themixture was further stirred at 60° C. for 1.5 hours. Into another vesselwere introduced sodium acetate (14 g) and desalted water (200 ml), thereaction mixture was added dropwise thereto under ice cooling. The pHwas adjusted to 6.1 by additionally adding sodium acetate (50 g). Theresulting mixture was extracted with a mixture of hexane and ethylacetate and the organic layer was washed with desalted water. Theorganic layer was separated, dried with anhydrous sodium sulfate, andconcentrated under reduced pressure to obtain an oily product (4.6 g,yield: quantitative).

To the oily product (4.5 g, 12 mmol) obtained were addedN,N-dimethylformamide (45 ml), triethylamine (3.9 ml, 31 mmol),propionic acid (1.1 ml, 15 mmol), and1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.4 g, 12mmol). After the mixture was stirred at room temperature for 16 hours,propionic acid (1.1 ml, 15 mmol) and1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.4 g, 12mmol) were added thereto. After the mixture was stirred for 23 hours,propionic acid (20 ml) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimidehydrochloride (10 g) were added thereto, followed by stirring for 45hours. Hexane and water were added to the reaction mixture and theorganic layer was separated, washed with water, and concentrated underreduced pressure. The resulting concentrate was purified by silica gelcolumn chromatography to obtain the intermediate C-8 (1.1 g).

<Synthesis of Intermediate C-9

The intermediate C-9 was synthesized from 3-chloroaniline and1-bromo-2-ethylhexane in the same manner as in the synthesis of theintermediate C-5.

<Synthesis of Intermediate C-10

A mixture of N-(3-aminophenyl)propanamide (10.0 g, 61 mmol),N,N-dimethylformamide (50 ml), 1-bromo-2-ethylhexane (35.3 g, 183 mmol),and potassium carbonate (33.7 g, 244 mmol) was stirred at 110° C. for 24hours. After being allowed to cool, the mixture was filtered and waterwas added to the filtrate, followed by extraction with toluene. Theresulting organic layer was concentrated and then purified by silica gelcolumn chromatography to obtain C-10 (7.6 g, yield 32%).

Example 1 Synthesis of Compound 1

While glacial acetic acid (11.4 ml) and 85% phosphoric acid (11.4 ml)were cooled with ice, M-1 (1.3 g, 4.5 mmol) was introduced into thesystem, 44% nitrosylsulfuric acid (1.6 g) was added dropwise thereto,and the whole was stirred to form a diazo solution. Into another vesselwere introduced C-1 (1.7 g, 4.4 mmol), THF (28 ml), and water (50 ml),and the whole was placed on an ice bath. The diazo solution was addeddropwise thereto to achieve coupling. The formed precipitate was takenout by filtration and then purified by silica gel column chromatographyto obtain the compound 1 (0.535 g, yield 18%).

Example 2 Synthesis of Compound 2

The compound 2 was synthesized from the intermediate M-3 and theintermediate C-2 in the same manner as in the synthesis of the compound1.

Example 3 Synthesis of Compound 3

The compound 3 was synthesized from the intermediate M-1 and theintermediate C-3 in the same manner as in the synthesis of the compound1.

Example 4 Synthesis of Compound 4

The compound 4 was synthesized from the intermediate M-3 and theintermediate C-4 in the same manner as in the synthesis of the compound1.

Example 5 Synthesis of Compound 5

The compound 5 was synthesized from the intermediate M-2 and theintermediate C-3 in the same manner as in the synthesis of the compound1.

Example 6 Synthesis of Compound 6

The compound 6 was synthesized from the intermediate M-4 and theintermediate C-5 in the same manner as in the synthesis of the compound1.

Example 7 Synthesis of Compound 7

The compound 7 was synthesized from the intermediate M-1 and theintermediate C-6 in the same manner as in the synthesis of the compound1.

Example 8 Synthesis of Compound 8

The compound 8 was synthesized from the intermediate M-4 and theintermediate C-1 in the same manner as in the synthesis of the compound1.

Example 9 Synthesis of Compound 9

While 2-amino-4-chloro-5-formylthiazole (2.1 g, 12.9 mmol), glacialacetic acid (12.6 ml), and propionic acid (2.9 ml) were cooled with ice,sulfuric acid (11.3 ml), desalted water (1.3 ml), and 44 wt %nitrosylsulfuric acid (4.1 g, 14.2 mmol) were added dropwise thereto andthe whole was stirred to form a diazo solution. Into another vessel wereintroduced C-3 (5.2 g, 12.9 mmol), THF (20 ml), sodium acetate (22.0 g),sulfamic acid (0.25 g), and water (60 ml), and the whole was placed onan ice bath. The diazo solution was added dropwise thereto to achievecoupling. The formed precipitate was taken out by filtration and thenpurified by silica gel column chromatography to obtain the compound 9(1.92 g, yield 26%).

Example 10 Synthesis of Compound 10

The compound 9 (0.80 g, 1.4 mmol) was dissolved in 2-ethylhexyl alcohol(8.0 ml). While a mixture thereof with 2-ethyl cyanoacetate (300 mg) wasstirred at room temperature, 0.3 equivalent amount of pyridine to theraw material was dissolved in 2-ethylhexyl alcohol and then addedthereto. The reaction mixture was added dropwise to water, filtered,washed with water, and then purified by silica gel column chromatography(0.32 g, yield 32%).

Example 11 Synthesis of Compound 11

While 2-amino-3-cyano-4-chloro-5-formylthiophene (0.5 g, 2.1 mmol),glacial acetic acid (3 ml), and propionic acid (0.7 ml) were cooled withice, sulfuric acid (2.7 ml), desalted water (0.3 ml), and 44 wt %nitrosylsulfuric acid (0.7 g, 2.3 mmol) were added dropwise thereto andthe whole was stirred to form a diazo solution. Into another vessel wereintroduced C-7 (0.95 g, 2.0 mmol), THF (5 ml), sodium acetate (5.7 g),sulfamic acid (0.06 mg), and water (20 ml), and the whole was placed onan ice bath. The diazo solution was added dropwise thereto to achievecoupling. The formed precipitate was taken out by filtration and thenpurified by silica gel column chromatography to obtain a blue compound.

While a mixture of the resulting blue compound (0.30 g, 0.5 mmol),n-BuOH (3.0 ml), and malononitrile (33 mg) was stirred at roomtemperature, 0.3 equivalent amount of pyridine to the raw material wasdissolved in n-BuOH and then added thereto. The reaction mixture wasadded dropwise to water, filtered, washed with water, and then purifiedby silica gel column chromatography to obtain the compound 11 (0.15 g,yield 46%).

Example 12 Synthesis of Compound 12

While a mixture of 2-amino-3,5-bis(ethoxycarbonyl)-4-methylthiophene(2.0 g, 7.8 mmol), glacial acetic acid (14 ml), propionic acid (2.8 ml),sulfuric acid (10.8 ml), and desalted water (1.2 ml) was cooled withice, 44 wt % nitrosylsulfuric acid (2.5 g, 8.6 mmol) was added dropwisethereto at 2° C. in the system and then the whole was stirred for 1 hourwhile a temperature of 0±5° C. in the system was maintained, to form adiazo solution. Into another vessel were introduced C-3 (2.9 g, 7.4mmol), tetrahydrofuran (40 ml), sulfamic acid (0.24 g), and sodiumacetate (5.7 g), and the diazo solution was added dropwise thereto underice cooling while a temperature of 0±5° C. in the system was maintained.Along the way, ice was additionally added. The reaction mixture wasfiltered and the filtrate was purified by silica gel columnchromatography to obtain the compound 12 (1.45 g, yield 28%).

Example 13 Synthesis of Compound 13

The compound 13 was synthesized from the intermediate M-1 and theintermediate C-8 in the same manner as in the synthesis of the compound1.

Example 14 Synthesis of Compound 14

The compound 14 was synthesized from the intermediate M-5 and theintermediate C-9 in the same manner as in the synthesis of the compound1.

Example 15 Synthesis of Compound 15

The compound 15 was synthesized from the intermediate M-1 and theintermediate C-5 in the same manner as in the synthesis of the compound1.

Comparative Example 1 Synthesis of Comparative Example Compound 1

The comparative example compound 1 was synthesized in accordance withExamples of International Publication WO2010/031860.

Comparative Example 2 Synthesis of Comparative Example Compound 2

The compound M-2 of JP-A-01-136787 was synthesized as the comparativeexample compound 2.

Compounds of Examples 1 to 15 and Comparative Examples 1 and 2 are shownbelow.

Comparative Example Compound 1

Comparative Example Compound 2

For the compounds 1 to 15 and the comparative example compounds 1 and 2,inks were prepared using n-decaline (relative permittivity 2.0,solubility in water 1 mg/L or less), Isopar M (manufactured by ExxonMobil Corporation, containing about 75% of branched saturatedhydrocarbons having 13 to 17 carbon atoms, relative permittivity 2.1,solubility in water 1 mg/L or less), Isopar L (manufactured by ExxonMobil Corporation, containing mainly branched saturated hydrocarbonshaving 11 to 12 carbon atoms and about 20% of branched saturatedhydrocarbons having 13 to 17 carbon atoms, relative permittivity 1.9,solubility in water 1 mg/L or less), a mixed solvent of n-decane/IsoparL (mixing ratio (mass ratio) 1/1, relative permittivity 1.9, solubilityin water 1 mg/L or less), or a mixed solvent of Isopar L/decaline(mixing ratio (mass ratio) 9/1, relative permittivity 1.9, solubility inwater 1 mg/L or less) as a solvent.

The solution colors, absorption-maximum wavelength (λ_(max)), solubilityC at 5° C., molar extinction coefficient ε, and εC for each solvent aresummarized in Tables 4 to 8.

<Method for Measuring Relative Permittivity of Sovent>

It is measured by the impedance meter method using a precision LCR meter4284A, manufactured by Agilent Technologies, Inc. Each ink or solventwas sandwiched between flat glass substrates which each had an ITOelectrode and which had been disposed parallel so as to face each otherat an electrode spacing of 30 μm. Thereafter, the equivalent parallelcapacity was measured while applying a test signal voltage of 0.1 V at afrequency of 1 kHz at 22° C. The relative permittivity was determinedthrough the calculation according to the following equation to evaluatethe solvent or ink.

Relative permittivity=(equivalent parallel capacity)×(electrodespacing)/(electrode area)/(permittivity in vacuum (ε₀))

<Method for Measuring Solubility of Solvent in Water>

Pure water (30 g) and a solvent (8 g) were introduced into 110 ml of avial, which was shaken 200 times/minute for 4 hours in aconstant-temperature tank at 25° C. The mixture after shaking wascentrifuged (6000×g, for 5 minutes), the aqueous layer was sampled, andthe concentration of the solvent dissolved was quantitatively determinedby gas chromatography. Since Isopar was not a single compound but amixture, the quantitative determination was performed as TOC (totalorganic carbon), which was converted into solubility according to thefollowing equation, the average molecular weight being shown as Mw.

Solubility [mg/L]=TOC [mg/L]×(14Mw/{12(Mw−2)}

In the case of a mixed solvent in which two or more kinds of solventswere mixed, the solubility in water was determined by multiplying thesolubility of each solvent in water by each molar fraction and summingup the resulting products.

In the case where the solvent species used is unclear, the solubility inwater can be measured by the above method through identification of thesolvent species by mass spectroscopy or the like.

<Method for Measuring Absorption-Maximum Wavelength λ_(Max) and MolarExtinction Coefficient ε>

Each of the compounds 1 to 15 and the comparative example compounds 1and 2 (1 mg each) was dissolved in each solvent (100 ml) and measurementof absorption spectra was performed on Hitachi spectrophotometer U-4100using a quartz cell having an optical path length for measurement of 10mm. From the resulting spectra, absorption-maximum wavelength λ_(max)(nm) and molar extinction coefficient ε (L·mol⁻²·cm⁻¹) were determined.

<Method for Measuring Solubility C and εC>

The solubility C of each compound in each solvent was measured asfollows.

Each compound was added to each solvent until a dissolution residue cameto remain, and the mixture was subjected to an ultrasonic treatment for30 minutes at 30° C. After the mixture was allowed to stand at 5° C. for24 hours, centrifugal filtration was performed through a filter of 0.1μm using a microcentrifuge (centrifugal force 5200×g). The resultingsaturated solution was diluted to an appropriate concentration, andmeasurement of absorption spectra was performed on Hitachispectrophotometer U-4100 using a quartz cell having an optical pathlength for measurement of 10 mm. The concentration of each compound wasdetermined from a relationship between the absorbance at theabsorption-maximum wavelength λ_(max) (nm) and the molar extinctioncoefficient ε (L·mol⁻¹·cm⁻¹) previously measured, and the solubility C(mol·L⁻¹) was calculated. Moreover, the value of the product of themolar extinction coefficient ε (L·mol⁻¹·cm⁻¹) and the solubility C(mol·L⁻¹), εC, was determined.

TABLE 4 Test results for n-decane Absorption- maximum ε (L · Colorwavelength Solubility mol⁻¹ · ε · C Compound tone (nm) (mol · L⁻¹) cm⁻¹)(cm⁻¹) Compound 1 blue 619 2.4 × 10⁻² 76000 1800 Compound 2 blue 635 2.7× 10⁻² 57000 1500 Compound 3 blue 667 1.4 × 10⁻¹ 73000 9900 Compound 4blue 638 2.7 × 10⁻² 66000 1800 Compound 5 blue 667 2.2 × 10⁻¹ 7500016000 Compound 6 blue 633 1.1 × 10⁻¹ 66000 7000 Compound 7 blue 640 1.4× 10⁻¹ 50000 6900 Compound 8 blue 637 5.9 × 10⁻² 79000 4700 Compound 9blue 617 5.8 × 10⁻² 57000 3300 Compound 10 blue 656 9.3 × 10⁻² 610005700 Compound 11 blue 642 8.9 × 10⁻² 60000 5300 Compound 12 blue 582 2.5× 10⁻¹ 46000 12000 Compound 13 blue 667 5.9 × 10⁻² 76000 4400 Compound14 red 546 1.5 × 10⁻¹ 47000 7100 Compound 15 blue 613 2.7 × 10⁻² 640001700 Comparative blue 652 2.7 × 10⁻² 17000 460 example compound 1Comparative red 512 1.0 × 10⁻⁵ or 34000 10 or example less less compound2

TABLE 5 Test results for tetradecane Absorption- maximum ε (L · Colorwavelength Solubility mol⁻¹ · ε · C Compound tone (nm) (mol · L⁻¹) cm⁻¹)(cm⁻¹) Compound 2 blue 637 2.7 × 10⁻² 54000 1500 Compound 3 blue 669 1.5× 10⁻¹ 73000 10600 Compound 4 blue 640 2.0 × 10⁻² 64000 1300 Compound 6blue 635 1.4 × 10⁻¹ 65000 9300 Compound 8 blue 639 4.4 × 10⁻² 79000 3500Compound 9 blue 618 3.4 × 10⁻² 59000 3300 Compound 10 blue 658 3.6 ×10⁻² 55000 2000 Comparative blue 651 9.4 × 10⁻² 17000 1600 examplecompound 1 Comparative red 514 1.0 × 10⁻⁵ or 39000 10 or example lessless compound 2

TABLE 6 Test results for Isopar M Absorption- maximum ε (L · Colorwavelength Solubility mol⁻¹ · ε · C Compound tone (nm) (mol · L⁻¹) cm⁻¹)(cm⁻¹) Compound 3 blue 668 1.5 × 10⁻¹ 72000 11100 Compound 6 blue 6341.6 × 10⁻¹ 65000 10400 Compound 8 blue 638 4.4 × 10⁻² 78000 3400Compound 9 blue 618 3.4 × 10⁻² 59000 2000 Compound 10 blue 657 6.4 ×10⁻² 54000 5500 Comparative blue 651 7.1 × 10⁻² 17000 1200 examplecompound 1 Comparative red 514 1.0 × 10⁻⁵ or 39000 10 or example lessless compound 2

TABLE 7 Test results for Isopar L Absorption- maximum ε (L · Colorwavelength Solubility mol⁻¹ · ε · C Compound tone (nm) (mol · L⁻¹) cm⁻¹)(cm⁻¹) Compound 3 blue 667 1.1 × 10⁻¹ 75000 8200

TABLE 8 Test results for mixed solvent of n- decane/Isopar L (mixingratio 1/1) Absorption- maximum ε (L · Color wavelength Solubility mol⁻¹· ε · C Compound tone (nm) (mol · L⁻¹) cm⁻¹) (cm⁻¹) Compound 3 blue 6676.3 × 10⁻² 75000 4700

Example 16 Preparation of Black Ink 1

A composition 1 composed of the compound 3 and the yellow compound A andthe red compound A to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less,manufactured by Tokyo Chemical Industry Co., Ltd.) to prepare the blackink 1. The recipe of the black ink 1 was as shown in Table 9.

Example 17 Preparation of Black Ink 2

A composition 2 composed of the compound 3 and the yellow compound A andthe red compound A to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less,manufactured by Tokyo Chemical Industry Co., Ltd.) to prepare the blackink 2. The recipe of the black ink 2 was as shown in Table 9.

Example 18 Preparation of Black Ink 3

A colorant composition 3 composed of the compound 3 and the yellowcompound A, the red compound A, and the blue compound A to be describedbelow were dissolved in n-decane (relative permittivity 2.0, solubilityin water 1 mg/L or less, manufactured by Tokyo Chemical Industry Co.,Ltd.) to prepare the black ink 3. The recipe of the black ink 3 was asshown in Table 9.

Example 19 Preparation of Black Ink 4

A composition 4 composed of the compound 3 and the yellow compound A,the red compound A, and the blue compound A to be described below weredissolved in n-decane (relative permittivity 2.0, solubility in water 1mg/L or less, manufactured by Tokyo Chemical Industry Co., Ltd.) toprepare the black ink 4. The recipe of the black ink 4 was as shown inTable 9.

Example 20 Preparation of Black Ink 5

A composition 5 composed of the compound 3 and the yellow compound A,the red compound A, the red compound B, the blue compound A, and theblue compound B to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less,manufactured by Tokyo Chemical Industry Co., Ltd.) to prepare the blackink 5. The recipe of the black ink 5 was as shown in Table 9.

Example 21 Preparation of Black Ink 6

A composition 6 composed of the compound 3 and the yellow compound A,the red compound C, and the blue compound A to be described below weredissolved in n-decane (relative permittivity 2.0, solubility in water 1mg/L or less, manufactured by Tokyo Chemical Industry Co., Ltd.) toprepare the black ink 6. The recipe of the black ink 6 was as shown inTable 9.

Example 22 Preparation of Black Ink 7

A composition 7 composed of the compound 3 and the yellow compound A,the red compound C, the red compound D, and the blue compound A to bedescribed below were dissolved in n-decane (relative permittivity 2.0,solubility in water 1 mg/L or less, manufactured by Tokyo ChemicalIndustry Co., Ltd.) to prepare the black ink 7. The recipe of the blackink 7 was as shown in Table 9.

Example 23 Preparation of Black Ink 8

A composition 8 composed of the compound 3 and the yellow compound A,the red compound C, and the blue compound A to be described below weredissolved in Isopar M (relative permittivity 2.1, solubility in water 1mg/L or less, manufactured by Exxon Mobil Corporation) to prepare theblack ink 8. The recipe of the black ink 8 was as shown in Table 9.

Example 24 Preparation of Black Ink 9

A composition 9 composed of the compound 3 and the yellow compound A,the red compound C, the red compound D, and the blue colorant A to bedescribed below were dissolved in Isopar M (relative permittivity 2.1,solubility in water 1 mg/L or less, manufactured by Exxon MobilCorporation) to prepare the black ink 9. The recipe of the black ink 9was as shown in Table 9.

Example 25 Preparation of Black Ink 10

A composition 10 composed of the compound 3, the compound 12, and theyellow compound A, the red compound C, and the red compound D to bedescribed below were dissolved in n-decane (relative permittivity 2.0,solubility in water 1 mg/L or less) to prepare the black ink 10. Therecipe of the black ink 10 was as shown in Table 9.

Example 26 Preparation of Black Ink 11

A composition 11 composed of the compound 3, the compound 12, and theyellow compound A, the red compound C, and the red compound D to bedescribed below were dissolved in n-decane (relative permittivity 2.0,solubility in water 1 mg/L or less) to prepare the black ink 11. Therecipe of the black ink 11 was as shown in Table 9.

Example 27 Preparation of Black Ink 12

A composition 12 composed of the compound 3, and the yellow compound Aand the red compound E to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less) toprepare the black ink 12. The recipe of the black ink 12 was as shown inTable 9.

Example 28 Preparation of Black Ink 13

A composition 13 composed of the compound 3, and the yellow compound A,the red compound C, the red compound D, and the blue compound A to bedescribed below were dissolved in n-decane (relative permittivity 2.0,solubility in water 1 mg/L or less) to prepare the black ink 13. Therecipe of the black ink 13 was as shown in Table 9.

Example 29 Preparation of Black Ink 14

A composition 14 composed of the compound 3, and the yellow compound A,the red compound B, the red compound C, the blue compound A, and theblue compound B to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less) toprepare the black ink 14. The recipe of the black ink 14 was as shown inTable 9.

Example 30 Preparation of Black Ink 15

A composition 15 composed of the compound 3, and the yellow compound A,the red compound B, the red compound C, and the blue compound B to bedescribed below were dissolved in n-decane (relative permittivity 2.0,solubility in water 1 mg/L or less) to prepare the black ink 15. Therecipe of the black ink 15 was as shown in Table 9.

Example 31 Preparation of Black Ink 16

A composition 16 composed of the compound 3, and the yellow compound A,the red compound C, the red compound D, and the blue compound A to bedescribed below were dissolved in n-decane (relative permittivity 2.0,solubility in water 1 mg/L or less) to prepare the black ink 16. Therecipe of the black ink 16 was as shown in Table 9.

Example 32 Preparation of Black Ink 17

A composition 17 composed of the compound 3, and the yellow compound A,the red compound C, the red compound D, and the blue compound A to bedescribed below were dissolved in n-decane (relative permittivity 2.0,solubility in water 1 mg/L or less) to prepare the black ink 17. Therecipe of the black ink 17 was as shown in Table 9.

Example 33 Preparation of Black Ink 18

A composition 18 composed of the compound 3, and the yellow compound Aand the red compound E to be described below were dissolved in Isopar L(relative permittivity 1.9, solubility in water 1 mg/L or less) toprepare the black ink 18. The recipe of the black ink 18 was as shown inTable 9.

Example 34 Preparation of Black Ink 19

A composition 19 composed of the compound 3, and the yellow compound Aand the red compound E to be described below were dissolved in a mixedsolvent of n-decane/Isopar L (mixing ratio (mass ratio) 1/1, relativepermittivity 1.9, solubility in water 1 mg/L or less) to prepare theblack ink 19. The recipe of the black ink 19 was as shown in Table 9.

Example 35 Preparation of Black Ink 20

A composition 20 composed of the compound 4, and the yellow compound Aand the red compound E to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less) toprepare the black ink 20. The recipe of the black ink 20 was as shown inTable 9.

Example 36 Preparation of Black Ink 21

A composition 21 composed of the compound 3, and the yellow compound Aand the red compound E to be described below were dissolved in a mixedsolvent of Isopar L/decaline (mixing ratio (mass ratio) 9/1, relativepermittivity 1.9, solubility in water 1 mg/L or less) to prepare theblack ink 21. The recipe of the black ink 21 was as shown in Table 9.

Example 37 Preparation of Black Ink 22

A composition 22 composed of the compound 3, and the yellow compound Aand the red compound E to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less) toprepare the black ink 22. The recipe of the black ink 22 was as shown inTable 9.

Example 38 Preparation of Black Ink 23

A composition 23 composed of the compound 3 and the compound 4, and theyellow compound A and the red compound E to be described below weredissolved in n-decane (relative permittivity 2.0, solubility in water 1mg/L or less) to prepare the black ink 23. The recipe of the black ink23 was as shown in Table 9.

Example 39 Preparation of Black Ink 24

A composition 24 composed of the compound 3 and the compound 4, and theyellow compound A and the red compound E to be described below weredissolved in Isopar L (relative permittivity 1.9, solubility in water 1mg/L or less) containing carbon black (Furnace Black, manufactured byMitsubishi Chemical Corporation) dispersed therein in a concentration of10% by mass, to prepare the black ink 24. The recipe of the black ink 24was as shown in Table 9.

Example 40 Preparation of Black Ink 25

A composition 25 composed of the compound 4, and the yellow compound Aand the red compound E to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less) toprepare the black ink 25. The recipe of the black ink 25 was as shown inTable 9.

Example 41 Preparation of Black Ink 26

A composition 26 composed of the compound 4, and the yellow compound Aand the red compound E to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less) toprepare the black ink 26. The recipe of the black ink 26 was as shown inTable 9.

Example 42 Preparation of Black Ink 27

A composition 27 composed of the compound 4, and the yellow compound Aand the red compound E to be described below were dissolved in n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less) toprepare the black ink 27. The recipe of the black ink 27 was as shown inTable 9.

Example 43 Preparation of Black Ink 28

A composition 28 composed of the compound 3, and the yellow compound Aand the red compound E to be described below were dissolved in Isopar L(relative permittivity 1.9, solubility in water 1 mg/L or less)containing carbon black (Furnace Black, manufactured by MitsubishiChemical Corporation) dispersed therein in a concentration of 10% bymass, to prepare the black ink 28. The recipe of the black ink 28 was asshown in Table 9.

Example 44 Preparation of Black Ink 29

A composition 29 composed of the compound 3 and the compound 4, and theyellow compound A and the red compound E to be described below weredissolved in n-decane (relative permittivity 2.0, solubility in water 1mg/L or less) to prepare the black ink 29. The recipe of the black ink29 was as shown in Table 9.

Yellow Compound A (Compound Described in International PublicationWO2009/063880)

Red Compound A

A mixture of H-1 (0.50 g, 3.3 mmol), glacial acetic acid (3 ml),propionic acid (0.7 ml), sulfuric acid (2.7 ml), and desalted water (0.3ml) were cooled on an ice bath, 44 wt % nitrosylsulfuric acid (1.0 g,3.6 mmol) was added dropwise thereto at 1° C. in the system, and thenthe whole was stirred for 1 hour while a temperature of 0±5° C. in thesystem was maintained, to obtain a diazo solution. Into another vesselwere introduced C-1 (0.81 g, 3.1 mmol), tetrahydrofuran (40 ml),sulfamic acid (0.06 g, 0.6 mmol), and sodium acetate (5.7 g), and thediazo solution was added dropwise thereto under ice cooling while atemperature of 0±5° C. in the system was maintained. Along the way, iceand tetrahydrofuran (40 ml) were additionally added. After thecompletion of the dropwise addition, an aqueous sodium acetate solutionwas added to adjust the pH to 4. After extraction with toluene, theresulting extract was concentrated under reduced pressure, theconcentrate was purified by silica gel column chromatography, and theformed solid was washed with methanol/water (1/1 (volume ratio)) tosynthesize the red compound A (0.45 g, yield 32%).

Red Compound B

The red compound B was synthesized in the same manner as in the case ofthe red compound A except that H-2 was used instead of H-1 and C-5 wasused instead of C-1.

Red Compound C

The red compound C was synthesized in the same manner as in the case ofthe red compound A except that C-10 was used instead of C-1.

Red Compound D

The red compound D was synthesized in the same manner as in the case ofthe red compound A except that C-2 was used instead of C-1.

Red Compound E

The red compound E was synthesized in the same manner as in the case ofthe red compound A except that H-2 was used instead of H-1.

Blue Compound A (Compound Described in JP-A-11-124510)

Blue Compound B (Compound Described in JP-A-2000-313174)

Comparative Example 3

Sudan Black B (manufactured by Tokyo Chemical Industry Co., Ltd.) thatis a commercially available oil-soluble black dye was added to n-decane(relative permittivity 2.0, solubility in water 1 mg/L or less) until adissolution residue came to remain, and the mixture was subjected to anultrasonic treatment for 30 minutes at 30° C. After the mixture wasallowed to stand at 5° C. for 24 hours, centrifugal filtration wasperformed through a filter of 0.1 μm using a microcentrifuge(centrifugal force 5200×g). The resulting saturated n-decane solutionwas diluted to an appropriate concentration. When the solubility of thecompound was calculated from a relationship with the extinctioncoefficient previously measured, the solubility was 0.13% by mass.

A saturated decane solution of Sudan Black B was prepared and used as anink of Comparative Example 3.

TABLE 9 Solvent Mixed Mixed solvent of solvent of n-decane/Isopar IsoparL/decaline CB/ n- Isopar L (mixing (mixing Isopar L Compound YellowDecane M Isopar L ratio 1/1) ratio 1/1) dispersion Compound 3 Compound 412 Compound A (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) Black ink 1 16.000— — — — — 1.700 — — 1.100 Black ink 2 0.780 — — — — — 0.083 — — 0.056Black ink 3 0.730 — — — — — 0.083 — — 0.053 Black ink 4 0.710 — — — — —0.083 — — 0.080 Black ink 5 0.570 — — — — — 0.083 — — 0.110 Black ink 60.650 — — — — — 0.100 — — 0.110 Black ink 7 0.640 — — — — — 0.100 — —0.110 Black ink 8 — 0.640 — — — — 0.100 — — 0.110 Black ink 9 — 0.640 —— — — 0.100 — — 0.110 Black ink 10 0.566 — — — — — 0.098 — 0.016 0.062Black ink 11 0.563 — — — — — 0.098 — 0.016 0.062 Black ink 12 0.814 — —— — — 0.083 — — 0.056 Black ink 13 0.702 — — — — — 0.100 — — 0.078 Blackink 14 0.770 — — — — — 0.025 — — 0.047 Black ink 15 0.720 — — — — —0.050 — — 0.078 Black ink 16 0.880 — — — — — 0.123 — — 0.078 Black ink17 0.885 — — — — — 0.123 — — 0.078 Black ink 18 — — 0.415 — — — 0.066 —— 0.045 Black ink 19 — — — 0.711 — — 0.040 — — 0.027 Black ink 20 0.754— — — — — — 0.125 — 0.063 Black ink 21 — — — — 0.814 — 0.083 — — 0.056Black ink 22 0.495 — — — — — 0.250 — — 0.130 Black ink 23 0.480 — — — —— 0.100 0.165 — 0.130 Black ink 24 — — — — — 1.000 0.070 0.110 — 0.053Black ink 25 0.758 — — — — — — 0.120 — 0.062 Black ink 26 0.833 — — — —— — 0.083 — 0.043 Black ink 27 0.682 — — — — — — 0.158 — 0.082 Black ink28 — — — — — 0.897 0.069 — — 0.007 Black ink 29 0.601 — — — — — 0.0770.127 — 0.101 Ink of — — — — — — — — — — Comparative Example 3 Red RedRed Red Red Blue Blue Sudan Compound A Compound B Compound C Compound DCompound E Compound A Compound B Black B (g) (g) (g) (g) (g) (g) (g)(mg) Black ink 1 0.940 — — — — — — — Black ink 2 0.080 — — — — — — —Black ink 3 0.080 — — — — 0.050 — — Black ink 4 0.080 — — — — 0.050 — —Black ink 5 0.080 0.019 — — — 0.033 0.100 — Black ink 6 — — 0.095 — —0.050 — — Black ink 7 — — 0.070 0.030 — 0.050 — — Black ink 8 — — 0.095— — 0.050 — — Black ink 9 — — 0.070 0.030 — 0.050 — — Black ink 10 — —0.012 0.046 — — — — Black ink 11 — — 0.012 0.048 — — — — Black ink 12 —— — — 0.047 — — — Black ink 13 — — 0.024 0.056 — 0.040 — — Black ink 14— 0.024 0.025 — — 0.025 0.084 — Black ink 15 — 0.025 0.030 — — — 0.101 —Black ink 16 — — 0.024 0.056 — 0.040 — — Black ink 17 — — 0.024 0.050 —0.040 — — Black ink 18 — — — — 0.038 — — — Black ink 19 — — — — 0.023 —— — Black ink 20 — — — — 0.059 — — — Black ink 21 — — — — 0.047 — — —Black ink 22 — — — — 0.125 — — — Black ink 23 — — — — 0.125 — — — Blackink 24 — — — — 0.076 — — — Black ink 25 — — — — 0.060 — — — Black ink 26— — — — 0.041 — — — Black ink 27 — — — — 0.079 — — — Black ink 28 — — —— 0.028 — — — Black ink 29 — — — — 0.096 — — — Ink of — — — — — — —13.000 Comparative Example 3

<Hue Evaluation>

Spectra were measured using a cell having an optical path length formeasurement of 0.01 mm for Black inks 1 to 20 and the ink of ComparativeExample 3, using a cell having an optical path length for measurement of0.004 mm for black inks 21 and 25 to 28, and using a cell having anoptical path length for measurement of 0.002 mm for black inks 22 to 24and 29. Color measurement was made using the color calculation programattached to Hitachi spectrophotometer U-4100, under the conditions ofD65 light source and a viewing angle of 2 degrees. Thus, each ink wasquantitatively evaluated for hue.

The results of the hue evaluation for black inks 1 to 29 and the ink ofComparative Example 3 are shown in Table 10.

TABLE 10 Optical path length Hue evaluation results Black ink formeasurement (mm) L* a* b* C* Black ink 1 0.01 8.89 2.32 4.24 4.83 Blackink 2 0.01 3.85 9.51 0.75 9.54 Black ink 3 0.01 1.01 3.08 −2.85 4.20Black ink 4 0.01 1.18 2.17 0.68 2.27 Black ink 5 0.01 0.26 0.33 0.200.39 Black ink 6 0.01 0.40 0.74 0.42 0.85 Black ink 7 0.01 0.43 0.810.48 0.94 Black ink 8 0.01 0.29 0.59 0.28 0.65 Black ink 9 0.01 0.320.60 0.29 0.67 Black ink 10 0.01 0.04 0.01 −0.02 0.02 Black ink 11 0.010.81 0.02 −0.02 0.03 Black ink 12 0.01 2.12 0.76 1.41 1.61 Black ink 130.01 0.05 0.02 −0.01 0.02 Black ink 14 0.01 0.18 0.38 0.09 0.39 Blackink 15 0.01 0.10 0.08 0.03 0.08 Black ink 16 0.01 0.05 0.01 −0.02 0.02Black ink 17 0.01 0.04 0.01 −0.02 0.02 Black ink 18 0.01 0.06 0.01 −0.010.02 Black ink 19 0.01 1.30 0.44 0.75 0.87 Black ink 20 0.01 0.04 0.04−0.01 0.04 Black ink 21 0.004 12.69 2.41 3.30 4.08 Black ink 22 0.0024.98 1.22 −0.63 1.37 Black ink 23 0.002 1.88 2.50 −5.07 5.65 Black ink24 0.002 9.23 0.52 −8.23 8.25 Black ink 25 0.004 1.10 0.46 −0.44 0.64Black ink 26 0.004 13.90 2.50 −5.07 5.65 Black ink 27 0.004 1.00 0.42−0.38 0.56 Black ink 28 0.004 0.84 0.17 −0.90 0.91 Black ink 29 0.00210.88 −0.61 −2.76 2.82 Ink of Comparative 0.01 91.80 1.51 −1.63 2.22Example 3

It is realized from Table 10 that black inks 1 to 29 have a value of L*close to 0 as compared with the ink of Comparative Example 3 and C* of10 or less, and are satisfactory black inks having an excellent blackhue.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

The present application is based on Japanese Patent Application No.2011-113759 filed on May 20, 2011, Japanese Patent Application No.2011-219414 filed on Oct. 3, 2011, Japanese Patent Application No.2012-005119 filed on Jan. 13, 2012, and Japanese Patent Application No.2012-086605 filed on Apr. 5, 2012, and the contents are incorporatedherein by reference.

INDUSTRIAL APPLICABILITY

The ink and azo compound of the invention are suitably used for displaysand optical shutters, especially, for example, suitably used aselectrowetting displays such as electronic paper and as electrophoreticdisplays.

1. An ink comprising: a solvent having a relative permittivity of 3 orless, as measured at a frequency of 1 kHz and at 22° C., and having asolubility in water of 20 mg/L or less at 25° C.; and an azo compound,the azo compound being represented by the following general formula (I):

wherein R¹, R², D¹, A¹, and A² each independently represent an arbitrarysubstituent, m represents an integer of 1 to 4, and when m is 2 orlarger, two or more D¹ groups present in one molecule may be the same ordifferent, and X represents a nitrogen atom or an optionally substitutedmethine group.
 2. The ink according to claim 1, wherein the solventcontains at least one selected from the group consisting of hydrocarbonsolvents, silicone oils, and fluorocarbon solvents.
 3. The ink accordingto claim 1, wherein the product of a molar extinction coefficient ε(L·mol⁻¹·cm⁻¹) at the absorption-maximum wavelength of an n-decanesolution of the azo compound and a saturated concentration C (mol·L⁻¹)of the azo compound in n-decane at 5° C., εC, is 1,000 cm⁻¹ or larger.4. The ink according to claim 1, which further comprises at least oneselected from the group consisting of heterocyclic compounds, cyanovinylcompounds, and anthraquinone compounds.
 5. The ink according to claim 4,wherein the heterocyclic compound is at least one selected from thegroup consisting of the following general formulae (III) to (V):

wherein R¹⁰¹, R¹⁰², D³, and D⁴ each independently represent an arbitrarysubstituent, e represents an integer of 1 to 5, and when e is 2 orlarger, two or more D³ groups present in one molecule may be the same ordifferent, and g represents an integer of 1 to 4, and when g is 2 orlarger, two or more D⁴ groups present in one molecule may be the same ordifferent;

wherein R²⁰¹, R²⁰², R²⁰³, R²⁰⁴, R²⁰⁵, R²⁰⁶, R²⁰⁷, and R²⁰⁸ eachindependently represent an arbitrary substituent and Z represents anitrogen atom or an optionally substituted methine group;

wherein R³⁰¹, R³⁰², D⁵, and D⁶ each independently represent an arbitrarysubstituent, l represents an integer of 1 to 4, and when 1 is 2 orlarger, two or more D⁵ groups present in one molecule may be the same ordifferent, and j represents an integer of 1 to 4, and when j is 2 orlarger, two or more D⁶ groups present in one molecule may be the same ordifferent.
 6. The ink according to claim 4, wherein the cyanovinylcompound is represented by the following general formula (VI):

wherein R⁴⁰¹, R⁴⁰², R⁴⁰³, R⁴⁰⁴, and D⁷ each independently represent anarbitrary substituent and r represents an integer of 1 to 4, and when ris 2 or larger, two or more D⁷ groups present in one molecule may be thesame or different.
 7. The ink according to claim 4, wherein theanthraquinone compound is represented by the following general formula(VII):

wherein D⁸ represents an arbitrary substituent and t represents aninteger of 1 to 8, and when t is 2 or larger, two or more D⁸ groupspresent in one molecule may be the same or different.
 8. The inkaccording to claim 1, which is for use in a display or optical shutter.9. A display comprising a display part containing the ink according toclaim 1, wherein an image is displayed by controlling voltageapplication to the display part.
 10. The display according to claim 9,wherein the display part further contains electrophoretic particles oran aqueous medium.
 11. The display according to claim 9, wherein animage is displayed by changing a colored state by means of voltageapplication.
 12. The display according to claim 9, wherein an image isdisplayed by an electrowetting system or an electrophoretic system. 13.An electronic paper which comprises the display according to claim 9.14. An azo compound represented by the following general formula (VIII):

wherein R⁶⁰¹ and R⁶⁰² each independently represent an optionallysubstituted branched alkyl group having 7 to 20 carbon atoms, D⁹represents a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, an —NHCOR⁶⁰³ group, or an—NHSO₂R⁶⁰⁸ group, R⁶⁰³ and R⁶⁰⁸ each independently represent anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms, arepresents an integer of 1 to 4, and when a is 2 or larger, two or moreD⁹ groups present in one molecule may be the same or different, A³represents a halogen atom, a cyano group, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, an optionally substituted heteroarylgroup having 2 to 20 carbon atoms, an optionally substituted alkoxygroup having 1 to 20 carbon atoms, or a —COOR⁶⁰⁴ group, R⁶⁰⁴ representsan optionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms, A⁴represents a halogen atom, an optionally substituted alkyl group having1 to 20 carbon atoms, an optionally substituted alkenyl group having 2to 20 carbon atoms, an optionally substituted alkylcarbonyl group having2 to 20 carbon atoms, an optionally substituted alkoxycarbonyl grouphaving 2 to 20 carbon atoms, a formyl group, an R⁶⁰⁵OOC(NC)C═CH— group,or an NC(NC)C═CH— group, R⁶⁰⁵ represents an optionally substituted alkylgroup having 1 to 20 carbon atoms, an optionally substituted aryl grouphaving 6 to 20 carbon atoms, or an optionally substituted heteroarylgroup having 2 to 20 carbon atoms, X² represents a nitrogen atom, or amethine group which may have a halogen atom, a cyano group, or a—COOR⁶⁰⁷ group as a substituent, and R⁶⁰⁷ represents an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, or an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms.
 15. An azocompound represented by the following general formula (IX):

wherein R⁷⁰¹ and R⁷⁰² each independently represent an optionallysubstituted branched alkyl group having 5 to 20 carbon atoms, D¹¹represents a hydrogen atom, a halogen atom, an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substitutedalkoxy group having 1 to 20 carbon atoms, an —NHCOR⁷⁰³ group, or an—NHSO₂R⁷⁰⁸ group, R⁷⁰³ and R⁷⁰⁸ each independently represent anoptionally substituted alkyl group having 1 to 20 carbon atoms, anoptionally substituted aryl group having 6 to 20 carbon atoms, or anoptionally substituted heteroaryl group having 2 to 20 carbon atoms, drepresents an integer of 1 to 4, and when d is 2 or larger, two or moreD¹¹ groups present in one molecule may be the same or different, A⁵represents a hydrogen atom, a halogen atom, a cyano group, an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms, an optionallysubstituted alkoxy group having 1 to 20 carbon atoms, or a —COOR⁷⁰⁴group, R⁷⁰⁴ represents an optionally substituted alkyl group having 1 to20 carbon atoms, an optionally substituted aryl group having 6 to 20carbon atoms, or an optionally substituted heteroaryl group having 2 to20 carbon atoms, D¹⁰ represents a hydrogen atom, a halogen atom, a cyanogroup, an optionally substituted alkyl group having 1 to 20 carbonatoms, an optionally substituted alkoxy group having 1 to 20 carbonatoms, a —COOR⁷⁰⁶ group, a —COR⁷⁰⁹ group, or an —OCOR⁷¹⁰ group, brepresents an integer of 1 to 5, and when b is 2 or larger, two or moreD¹⁰ groups present in one molecule may be the same or different, R⁷⁰⁶,R⁷⁰⁹, and R⁷¹⁰ each independently represent an optionally substitutedalkyl group having 1 to 20 carbon atoms, an optionally substituted arylgroup having 6 to 20 carbon atoms, or an optionally substitutedheteroaryl group having 2 to 20 carbon atoms, X³ represents a nitrogenatom, or a methine group which may have a halogen atom, a cyano group,or a —COOR⁷⁰⁷ group as a substituent, and R⁷⁰⁷ represents an optionallysubstituted alkyl group having 1 to 20 carbon atoms, an optionallysubstituted aryl group having 6 to 20 carbon atoms, or an optionallysubstituted heteroaryl group having 2 to 20 carbon atoms.